Consumer Preferences for Vietnamese OCOP Dong Vermicelli: Implications for Water Conservation and Circular Economy in Mountainous Agriculture

Abstract

Vietnam’s One Commune One Product (OCOP) program is pivotal for rural socio-economic development, yet traditional production, such as Dong vermicelli, poses environmental challenges regarding water use and waste. While the circular economy (CE) presents a viable solution, its adoption is hindered by unquantified market-based incentives. This study addresses this gap by empirically evaluating consumer willingness-to-pay (WTP) for OCOP Dong vermicelli featuring specific CE attributes. A discrete choice experiment (DCE) integrated with a latent class model (LCM) was administered to 606 Vietnamese consumers to quantify preferences for five attributes: OCOP star rating, traceability, wastewater treatment, residue management, and price. The analysis revealed significant preference heterogeneity, identifying a key segment of “OCOP Advocates” characterized by younger demographics, higher income, and greater CE awareness. This group demonstrated a significant WTP premium: 9.3% for verified wastewater treatment, 4.4% for residue repurposing, and 6.5% for a 5-star OCOP rating, relative to baseline products. These results provide robust empirical evidence for a market-based pathway to integrating CE principles within a developing country’s traditional food sector. They highlight a viable market for sustainable OCOP products, incentivizing producers to adopt water-saving and circular practices. The findings suggest that policymakers can foster sustainable mountainous agriculture by strengthening OCOP certification standards and enhancing consumer awareness, thereby aligning market demand with environmental stewardship.

Keywords

consumer preferences water conservation circular economy sustainable agriculture one commune one product Dong vermicelli latent class analysis mountainous region Vietnam

Introduction

The agricultural sector in Vietnam remains central to the national economy, sustaining rural and mountainous livelihoods, ensuring food security, reducing poverty, and contributing significantly to export revenue (Dung et al., 2022; Newman et al., 2020; H. Q. Nguyen et al., 2019; Phi & Bui, 2022; Tran et al., 2021). To foster rural development, the government has introduced the One Commune One Product (OCOP) program, which mobilizes local resources and cultural assets to create high-quality, value-added products (Knight, 1994; Kurokawa, 2009). Among these, OCOP Dong vermicelli, produced from edible canna (Canna edulis), serves as both an important source of income and a marker of cultural identity for ethnic minority groups in the northern mountainous regions of Vietnam.

Despite these socio-economic benefits, OCOP Dong vermicelli production generates large volumes of wastewater and residue that threaten water quality and local ecosystems (P. B. N. Nguyen et al., 2024; Pham, 2020). Circular economy (CE) principles offer a promising framework for mitigating the impact of reuse, recycling, and resource regeneration (Alhawari et al., 2021; Awan et al., 2020; Geisendorf & Pietrulla, 2018; Murray et al., 2017). Circular practices such as repurposing residues into organic fertilizers, treating and reusing wastewater for irrigation, enhancing soil fertility, managing waste, and promoting water conservation, potentially add value to OCOP Dong vermicelli production depletion and foster more sustainable production systems (Haque et al., 2023; Mannina et al., 2022; Morseletto et al., 2022; Rodias et al., 2021; Rodríguez-Espinosa et al., 2023). Although these CE practices are essential, OCOP-certified Dong vermicelli production only elevates a product’s market status and quality perception, but does not explicitly mandate or certify advanced CE practices. Growing consumer demand for sustainably produced goods presents an opportunity to accelerate the implementation of CE principles. While the OCOP label provides a baseline for quality, it is unclear whether a market exists for OCOP Dong vermicelli products that integrate supplementary, verifiable sustainability attributes. Therefore, this study addresses the core question: Are consumers willing to pay an additional premium for OCOP-certified Dong vermicelli products that feature verified CE attributes?

Prior studies have shown that environmentally conscious consumers are often willing to pay a premium for products incorporating sustainability attributes, such as eco-labels, traceability, and certification (Sama et al., 2018; Sánchez-Bravo et al., 2021; Trang et al., 2025; Villanueva et al., 2025). This literature underscores the influence of sustainability and certification on consumer behavior in global food and agricultural markets. For example, eco-labeling in coffee and organic certification in fruits have been shown to affect purchasing decisions significantly (Aminravan et al., 2025; Gatti et al., 2022, 2024; Liu et al., 2019; Maaya et al., 2018), such studies typically emphasize international commodities rather than localized, culturally embedded products. However, most existing studies focus on broad agricultural products or international contexts, offering limited insights into localized programs such as Vietnam’s OCOP. Moreover, whether these global findings translate into consumer behavior towards specific OCOP products, such as Dong vermicelli, remains an open question.

Despite this progress, several gaps remain in the literature. First, little is known about how consumers respond to sustainability attributes in the context of OCOP products, particularly Dong vermicelli. Second, few studies explicitly link willingness-to-pay (WTP) for attributes such as wastewater treatment, residue management, traceability, and certification with resource-efficient practices in localized supply chains. Without this link, it is challenging to determine whether consumer demand can effectively motivate producers to adopt CE practices. Third, evidence on consumer heterogeneity in developing countries is scarce. In particular, limited knowledge exists on how preferences vary across socio-demographic groups in Vietnam’s mountainous regions, leaving unanswered questions about how such heterogeneity can inform effective policies for sustainable rural development.

To address these gaps, this study aims to (1) analyze consumer preferences for OCOP Dong vermicelli attributes related to water conservation and CE practices (wastewater treatment and residue management), as well as product-specific features (star rating, traceability), and (2) identify distinct consumer segments based on their preferences and socio-demographic characteristics. To achieve these aims, we employ a discrete choice experiment (DCE) and a latent class model (LCM), which enable us to quantify WTP and identify heterogeneous consumer profiles. By linking consumer demand with sustainable production practices, this study contributes to advancing the adoption of CE in rural food systems, safeguarding water resources, and supporting the livelihoods of ethnic minority communities in the mountainous agricultural sector of Vietnam.

Following this introduction, we review the literature on consumer preferences for sustainable products, as well as the agricultural application of water conservation and the CE principles in Section “Background.” This theoretical foundation informs our research methodology, which is detailed in Section “Methodology.” Section “Results and Discussions” presents the results and discussions of our analysis. Section “Limitations and Future Research” concludes the paper with a discussion of its limitations and suggestions for future research.

Background

OCOP Dong Vermicelli and Its Pivotal Role in the Quality and Origin Assurance Framework and Rural Development

The One Village One Product (OVOP) movement, initiated in Oita prefecture, Japan, in 1979, exemplified how rural communities could mobilize endogenous resources and cultural capital to produce distinctive, high-value commodities. By fostering specialization, the OVOP revitalized declining rural economies, doubling household incomes within two decades (Haraguchi, 2008), from $13,000 in 1979 to $26,000 in 2003 (Perdue et al., 2013). Its success has facilitated its widespread adoption across Asia, where it is now regarded as a paradigm of rural economic transformation (Knight, 1994).

Vietnam’s One Commune One Product (OCOP) program, which was adapted from the OVOP, constitutes a state-administered certification framework aimed at enhancing the market competitiveness of indigenous and specialty products from rural localities. OCOP products are categorized into six groups (foods, beverages, medicinal herbs, handicrafts, ornamental plants, and community-based tourism services). They were evaluated for star-based ranking (from one to five). This evaluation is based on stringent criteria related to quality, safety, packaging, and marketability (Food and Agriculture Organization of the United Nations [FAO], 2022; Hoang Thanh et al., 2018). Consequently, products certified as OCOP serve as a powerful signal to consumers, primarily assuring them of the product’s origin and quality. Additionally, OCOP products play an important role in economic development, cultural preservation, livelihood diversification, and market expansion, thereby positioning them as a cornerstone of Vietnam’s rural development strategy (Trang et al., 2025).

Dong vermicelli, a traditional specialty in Vietnam’s northern mountainous provinces, exemplifies how OCOP certification can catalyze local product transformation. Produced from edible canna through artisanal processing techniques, Dong vermicelli is renowned for its clarity, elasticity, and purity, which can be achieved without chemical additives. The acquisition of OCOP certification has enabled Dong vermicelli producers to standardize production processes, enhance packaging quality, and achieve three- to five-star ratings, thereby expanding their market access. As a result, this product not only strengthens the economic resilience of ethnic minority households but also reinforces regional cultural identity, elevating a local staple into a nationally recognized symbol of community-based rural development.

However, this seemingly successful trajectory also reveals a deeper conceptual tension within the OCOP framework. While certification mechanisms prioritize product quality, branding, and market competitiveness, they do not explicitly assess or incentivize the environmental sustainability of production practices. This limitation reflects a broader contradiction between market rationality, emphasizing commercialization and value upgrading, and ecological rationality, which centers on resource conservation and environmental stewardship. As such, the OCOP-driven advancement of Dong vermicelli illustrates not only the potential for rural industrialization but also the risks of decoupling economic progress from ecological integrity. Addressing this disjunction forms the core analytical concern of this study, which seeks to examine how product standardization and certification systems can reconcile market imperatives with sustainability objectives in rural development contexts.

Environmental Externalities in OCOP Dong Vermicelli Production and the CE Pathway

While OCOP certification has successfully elevated the market status of Dong vermicelli, it does not inherently address the significant environmental externalities of its production. Specifically, starch extraction generates substantial volumes of untreated wastewater and fibrous residues, thereby creating localized ecological degradation and resource inefficiencies (P. B. N. Nguyen et al., 2024; Pham, 2020). Although OCOP certification enhances competitiveness and visibility, it fails to adequately mitigate these environmental externalities and does not explicitly mandate or certify advanced CE practices. Such omission risks undermine the long-term sustainability of the Dong vermicelli sector.

The CE framework provides a promising pathway to address these shortcomings. Core CE practices include wastewater treatment to minimize aquatic pollution and reuse arrowroot residues in animal feed or as biofertilizers (Bhandari et al., 2023; Kurniawan et al., 2021; López-Sánchez et al., 2022; Priyadharshini et al., 2021; Shahid et al., 2020; Su, 2021). Integrating these measures into the OCOP program would not only extend certification beyond quality assurance but also align rural development with global sustainability imperatives, thereby positioning Dong vermicelli as an exemplar of environmentally responsible rural enterprise. However, practical incorporation of such CE measures into local certification schemes remains underexplored.

Although CE principles have been widely applied in organic farming, horticulture, and agro-industrial systems to reduce ecological footprints and generate alternative revenue streams (Arruda et al., 2021; Barros et al., 2020; Haque et al., 2023; Prieto-Sandoval et al., 2018; Velasco-Muñoz et al., 2022), empirical evidence remains scarce for smallholder-based food systems. In Vietnam’s mountainous regions, where artisanal production predominates, little is known about the extent to which CE practices can complement OCOP certification to address unresolved environmental challenges. In practice, however, the adoption of CE measures depends not only on technical feasibility but also on consumer demand and the market’s willingness to reward environmentally responsible producers.

Despite a growing policy interest in sustainable rural development, several research gaps remain. First, little is known about how OCOP-certified enterprises operationalize environmental responsibility beyond compliance-based certification. Second, empirical studies have yet to explore how CE practices can be effectively integrated into small-scale, resource-constrained production contexts such as Dong vermicelli. Third, the behavioral and market conditions that influence producers’ willingness to adopt CE measures are poorly understood. Addressing these gaps is essential for advancing the theoretical and practical understanding of how product certification schemes can evolve toward environmentally sustainable rural governance.

Consumer Preferences for Verified Sustainability Attributes

Consumer demand is increasingly shaping the adoption of sustainability-oriented practices in food systems. Purchasing behavior is often influenced by verified sustainability attributes, such as traceability, eco-labels, and certifications, which connect food choices with environmental and social outcomes. A sustainable product is commonly defined as one that minimizes ecological harm, promotes social well-being, and ensures economic viability (Cook et al., 2023; Garcia-Garcia et al., 2021; Qu et al., 2024; Sánchez-Bravo et al., 2021). Increasing awareness of climate change, biodiversity loss, and natural resource depletion has heightened consumer sensitivity to such attributes (Hong et al., 2025; Li & Kallas, 2021), whereas product features such as health, chemical safety, and certification consistently influence preferences and WTP (Guo et al., 2020; Yin et al., 2017; Zhu et al., 2022). However, how these evolving consumer expectations translate into purchasing behavior toward regionally certified products remains unclear.

Although sustainability considerations increasingly shape consumer decision-making, preferences for specific sustainability credentials remain highly heterogeneous and context-dependent. Two important research gaps have emerged from this observation. First, limited empirical attention has been paid to how consumers perceive supplementary CE attributes, such as wastewater treatment or residue reuse, when incorporated into products that already carry established certifications, such as OCOP. Second, quantitative evidence of consumers’ WTP for such CE-enhanced attributes is largely absent, particularly within smallholder-based food systems in Vietnam’s mountainous regions. To address these gaps, this study examines consumer preferences and WTP for CE-integrated OCOP Dong vermicelli. In doing so, it extends the literature on CE integration into certified local products. It offers policy-relevant insights into how consumer demand drives sustainable and inclusive rural development.

Synthesized Research Gaps

To summarize, while prior research has examined the concepts of OCOP certification, CE practices, and consumer WTP individually, empirical inquiry remains limited at their intersection. Specifically, few studies have investigated how consumers distinguish between established OCOP quality assurances and supplementary CE-related process attributes, such as wastewater treatment and residue repurposing. Moreover, evidence on consumers’ WTP for such enhanced sustainability features in already-certified products is particularly scarce in the Vietnamese context. Addressing these gaps, the present study employs DCE to assess whether integrating advanced CE practices into OCOP-certified production can generate both environmental and economic value, thereby establishing a viable business case for sustainable traditional products.

Methodology

Theoretical Framework and Methodological Justification

Theoretical Framework

This study is grounded in Lancaster’s theory of consumer choice and random utility theory, which together provide a rigorous framework for analyzing preferences and WTP for OCOP Dong vermicelli. Lancaster’s theory emphasizes that consumers derive utility not from the product itself but from its attributes, making it especially well-suited for examining multi-attribute goods (Gracia & De Magistris, 2008; Kuenne, 1998; Sohrabi et al., 2020; Wierenga, 1984), such as vermicelli, where quality, certification, and emerging CE features all matter. This attribute-based perspective enables the explicit analysis of trade-offs, as consumers may balance traditional product qualities with sustainability-related attributes, such as wastewater treatment and residue management. Random utility theory complements this framework by providing an econometric foundation for modeling choice behavior, conceptualizing utility as the sum of an observable component associated with product attributes and an unobservable component capturing individual heterogeneity (Boxall, 1999; Boxall & Adamowicz, 2002; Hess et al., 2018; Louviere et al., 2002; McFadden & Train, 2000). By framing choices probabilistically, random utility theory directly underpins discrete choice models, allowing for the estimation of both choice approaches on food and environmental economics to examine how consumer demand can incentivize the integration of sustainability into OCOP certification and, more broadly, rural development policy.

Justification for Methodological Approach

This study employs a Discrete Choice Experiment (DCE) as the primary methodological approach to quantify consumer preferences and WTP for the non-market attributes of OCOP Dong vermicelli. Grounded in Lancaster’s theory of consumer choice and random utility theory, DCE models utility as a function of product attributes rather than the product itself, making it particularly suited to credence attributes (Dahlhausen et al., 2018; Lizin et al., 2022), such as certification, wastewater treatment, and residue treatment. Unlike revealed preference methods, which are constrained by existing market conditions, DCE enables the valuation of novel or emerging attributes, including CE practices that are not yet widely implemented in OCOP vermicelli production (Louviere, 1992; Louviere et al., 2000).

Compared with alternative stated-preference methods, DCE offers distinct analytical advantages. While contingent valuation typically elicits WTP for a single attribute or product bundle, DCE requires respondents to make explicit trade-offs across multiple attributes, thereby revealing their relative importance and marginal WTP (Hanley et al., 2001). This capability is essential for understanding how consumers balance traditional quality cues (OCOP star rating and traceability) against sustainability features (wastewater and residue treatment) and associated price premiums. As a result, DCE provides richer behavioral insights than single-attribute valuation approaches. Furthermore, by presenting respondents with realistic choice scenarios that mirror actual purchasing decisions, DCE mitigates hypothetical bias more effectively than direct elicitation methods (Lusk & Schroeder, 2004). A core assumption is that individuals select the option yielding the highest utility, including the “opt-out” alternative, when none of the offered profiles is preferred (Mas-Colell et al., 1995). Including this opt-out alternative enhances realism and enables the estimation of demand elasticity.

With a strong methodological track record in food, agriculture, and environmental economics (Hong et al., 2025; Khai & Yabe, 2015; Trang & Tu, 2024; Tu et al., 2021; Wu et al., 2015), DCE ensures both analytical rigor and policy relevance, making it the most robust tool for assessing whether consumer demand can support the integration of CE practices into OCOP certification.

Specifically, the utility derived by consumer k when selecting alternative n from a set of M options within choice set C can be denoted as $U_{kn}$ . The utility a consumer obtains from OCOP Dong vermicelli is considered in two parts: $V_{kn}$ , which depends on the alternative’s attributes, and a random component $ε_{km}$ capturing nonsystematic or unique factors affecting utility that are not part of $V_{kn}$ . The utility of alternative n is defined as follows:

U_{kn} = V_{kn} + ε_{kn}

(1)

Hence, consumer k will choose alternative n if $U_{kn} > U_{km}$ . $\forall m \neq n$ . Accordingly, the probability that consumer k selects alternative n is expressed in the following manner:

P_{kn} = P (V_{kn} + ε_{kn} > V_{km} + ε_{km}; \forall m \in C m \neq n;

(2)

Research Design and Data Collection

Research Design

This study adopts a cross-sectional survey design incorporating a DCE to examine consumer preferences and willingness to pay for attributes of OCOP Dong vermicelli. A cross-sectional approach is appropriate for capturing consumer trade-offs at a specific point in time, while the DCE enables the systematic evaluation of multiple product attributes - including credence-based CE practices - within realistic purchase scenarios. Data were collected in Hanoi, Vietnam, between October 2024 and January 2025, a period covering both regular consumption and the Lunar New Year preparation season, when vermicelli consumption typically increases.

Hanoi was selected as the study site for three reasons. First, as Vietnam’s capital and largest urban center, it offers a heterogeneous consumer population with diverse socioeconomic backgrounds and food consumption behaviors, thereby supporting the external validity of the findings. Second, consumers in Hanoi have relatively high exposure to OCOP-certified products through government promotion campaigns and established retail channels, enhancing familiarity with OCOP labeling and quality signals. Third, the city’s population includes a substantial number of migrants from northern mountainous provinces where Dong vermicelli is traditionally produced, ensuring familiarity with the product among a meaningful share of respondents.

The research design integrates stated-preference data derived from the DCE with socio-demographic information collected via the survey questionnaire, enabling the analysis of preference heterogeneity and consumer segmentation. This integrated design supports the identification of distinct consumer groups with differing valuations of CE attributes and price sensitivity.

To strengthen internal validity, the research protocol incorporated several bias-mitigation measures commonly recommended for stated preference studies. Strategic bias was reduced by informing respondents that their choices would not directly influence prices or policy outcomes. Information bias was addressed through standardized attribute descriptions and visual aids, while hypothetical bias was mitigated by employing realistic price levels and including an opt-out alternative in each choice set to reflect real-world purchasing conditions.

Data Collection

Consistent with Orme’s (2010) guidelines for robust estimation in discrete choice experiments, a target sample size of approximately 600 respondents was established. To achieve this, a convenience sampling strategy was employed to recruit participants via face-to-face interviews in Hanoi, Vietnam. The final dataset comprised 606 valid respondents, yielding 2,424 choice observations. This sample size exceeds the benchmark of 500 commonly cited in recent empirical studies (Kušar et al., 2023; Mesidis et al., 2023; Torma & Thøgersen, 2024; Trang et al., 2025), ensuring adequate statistical power for both aggregate and complex model specifications. Ten trained research assistants approached potential respondents outside markets and supermarkets, ensuring access to a broad range of consumers. Before data collection, the assistants received specialized training on the survey structure, attribute descriptions, and choice experiment procedure, enabling them to clearly communicate the study objectives and accurately administer the DCE. When respondents were unfamiliar with OCOP Dong vermicelli, the assistants provided a brief explanation (approximately 3–4 min) of the product and the structure of the choice sets to ensure informed participation. Prior to the choice experiment, all respondents received a standardized introduction to the four attributes and their corresponding levels, supported by visual aids. Additionally, real examples of OCOP Dong vermicelli products were shown to enhance contextual understanding and facilitate thoughtful decision-making. After the survey, each participant received 50,000 VND in compensation for completing the questionnaire.

Design of the Discrete Choice Experiment for OCOP Dong Vermicelli

Attribute and Level Selection

To ensure the validity of the experimental design, a rigorous two-phase protocol was implemented to elicit and refine the relevant attributes prior to the main survey. Initially, a comprehensive review of extant literature on food quality cues, sustainability labeling, and circular economy (CE) practices—contextualized within the production of Dong vermicelli—yielded a preliminary pool of potential attributes. Subsequently, this list was validated and narrowed down through qualitative consultation, comprising focus group discussions with 20 consumers and in-depth interviews with three OCOP experts. Based on criteria of relevance and comprehensibility, five final attributes were established: OCOP star rating, traceability, wastewater treatment, residue treatment, and price.

OCOP Star Rating

As previously mentioned, the OCOP star rating was officially certified by the Vietnamese government. It serves as a government-endorsed quality cue that reduces information asymmetry and signals credibility. Prior studies have shown that consumers are willing to pay premiums for higher ratings (Ballco & Gracia, 2022; Trang et al., 2025; Wu et al., 2021).

In this study, OCOP Dong vermicelli were differentiated into three quality classifications: three-, four-, and five-star. These classifications are operationally defined and coded as “Three-star,”“Four-star,” and “Five-star.” The “Three-star” rating functions as the baseline, indicating the minimum quality standard for certified OCOP Dong vermicelli. Furthermore, this study posits that consumers demonstrate WTP for products associated with higher star ratings.

Traceability

Traceability refers to the extent to which a product provides sufficient information on its origin and production process, allowing the verification of its quality, safety, and authenticity (Benatia et al., 2022; Ruiz-Pastor & Mesa, 2023). This has become increasingly important in food markets, with evidence that consumers are willing to pay for reliable traceability information (X. Chen et al., 2021; Yin et al., 2017).

In this study, producers of OCOP Dong vermicelli provided the required traceability information as mandated by local and national authorities. However, from the consumer perspective, this information may or may not be perceived as sufficient. Therefore, the variable TRACE captures consumer perceptions of the sufficiency of traceability information (enough vs. not enough information) (see Table 1 for details).

Table 1.

Attributes and Their Respective Levels for OCOP Dong Vermicelli.

Attributes	Description	Levels
Star (STAR)	Indicates the product quality assigned by government rating and evaluation committees.	3 stars, 4 stars and 5 stars
Traceability(TRACE)	Indicates the existence or nonexistence of the bar code or QR code of the origin information of the products.	Yes: enough information for traceability No: not enough information
Wastewater treatment (WWATER)	Indicates information about the wastewater treatment in the product of OCOP Dong vermicelli is present.	Yes and No
Residue treatment (RESIDUE)	Indicates information about the residue in the production of OCOP Dong is treated.	Yes and No
Price (PRICE)	Price associated with a 500-gram pack of OCOP Dong vermicelli.	+5%, +10%, +15%, and 20%

Source. Designed by authors.

Wastewater Treatment

Vermicelli production is highly water-intensive and generates substantial wastewater from the washing, grinding, and starch extraction processes. If left untreated, this water poses environmental risks; however, treatment enables its reuse for irrigation and aligns with CE practices (Fito & Van Hulle, 2021; Silva, 2023). To capture consumer valuation of sustainable practices, wastewater treatment was coded as a binary attribute (yes/no). We expected positive preferences and a higher WTP for products linked to wastewater treatment.

In this study, we posited that consumers are willing to pay a premium for OCOP Dong vermicelli, contingent upon receiving information about wastewater treatment practices. Consequently, the attribute of information about the wastewater treatment of OCOP Dong vermicelli is categorized into two levels: Yes and No. This attribute was coded as WWATER.

Residue Treatment

Arrowroot processing generates fibrous residues, which, if unmanaged, contribute to local pollution. However, residues can be repurposed as compost, livestock feed, or biochar, enhancing resource efficiency and farmer income, while reducing environmental harm (Campos et al., 2020; Kamboj et al., 2024). Despite its potential, the consumer demand for residue treatment remains underexplored. This study includes residue treatment as a binary attribute (yes/no) and hypothesizes that consumers prefer vermicelli associated with residue recycling.

In this study, we posit that consumers are willing to pay a premium for OCOP Dong vermicelli when the residue is treated. The attribute of the information about the residue treatment of OCOP Dong vermicelli has two levels: Yes and No. This attribute was coded as RESIDUE.

Choice Sets Design

We randomly assigned participants to one of the four distinct survey versions. These versions were differentiated according to specific attributes and their corresponding levels, as shown in Table 1.

The attributes from Table 1 are explained as follows:

STAR: government-assigned product quality rating (3, 4, or 5 stars), coded with dummy variables; TRACE: availability of a barcode or QR code providing traceability information; coded 1 = Yes, 0 = No; WWATER: information on wastewater treatment practices; coded 1 = Yes, 0 = No; RESIDUE: information on residue treatment in production; coded 1 = Yes, 0 = No (see Table 1).

PRICE: quantifies the premium, expressed as a percentage, that consumers are WTP for a 500 g package of OCOP Dong vermicelli. This variable encompasses four distinct levels: 5%, 10%, 15%, and 20%. The determination of these specific percentage increments was guided by preliminary research indicating a consumer propensity to accept price premiums within the 5% to 20% range above the extant market price for OCOP Dong vermicelli. Moreover, the adoption of percentage-based price levels is predicated on the established theoretical understanding that consumers typically perceive price differentials in relative terms (i.e., percentages) rather than as absolute monetary values (Tait et al., 2019; Tienhaara et al., 2015). This approach is further supported by findings suggesting that percentage-based expressions of price changes hold greater cognitive salience for respondents than absolute figures (Snowball & Willis, 2006; Sy et al., 1997).

The primary objective of this investigation is to identify the specific product attributes of OCOP Dong vermicelli that hypothetical consumers consider most significant. This study focused on quantifying a utility function using the aforementioned attributes as independent variables. By doing this, the research integrated two attributes, each possessing two levels; two additional attributes, one with two levels and the other with three levels; and a final attribute with four levels. This configuration culminated in a comprehensive factorial design comprising 96 potential combinations (2 × 2 × 2 × 3 × 4). To navigate the intricacies associated with this design, the statistical software SPSS 22 was utilized to execute an orthogonal design methodology, leading to the creation of 16 unique attribute profiles (Addelman, 1972).

The OCOP Dong vermicelli products, designated explicitly as Products A and B, alongside a benchmark comparator (Product C), were treated as unbranded alternatives in this study. Consequently, to ensure a balanced and orthogonal presentation of attribute levels within the choice experiments, a cyclical or fold-over design methodology was employed. Following this established approach, the level of a designated attribute was systematically incremented by one unit for each subsequent alternative presented within the same choice set (Louviere et al., 2000). The resulting 16 unique choice sets were randomly allocated across four distinct versions of the questionnaire, with each participant tasked with evaluating the four choice sets. In total, 16 hypothetical product profiles were constructed to facilitate the assessment of consumer WTP for the various attributes characterizing the Dong vermicelli product, as detailed in Table 2. Table 3 presents the sample choice set.

Table 2.

Experimental OCOP Dong Vermicelli Formulations Employed in the Consumer Preferences Analysis.

Hypothetical product	Star	Traceability	Wastewater treatment	Residue treatment	Price
1	3 stars	Yes	No	No	15%
2	5 stars	No	No	Yes	10%
3	4 stars	No	Yes	Yes	15%
4	3 stars	Yes	Yes	Yes	20%
5	5 stars	Yes	Yes	Yes	20%
6	4 stars	Yes	Yes	No	10%
7	5 stars	No	Yes	No	5%
8	5 stars	Yes	No	No	15%
9	4 stars	No	Yes	Yes	15%
10	4 stars	No	No	No	20%
11	4 stars	Yes	Yes	No	10%
12	4 stars	Yes	No	Yes	5%
13	4 stars	No	No	No	20%
14	3 stars	No	No	Yes	10%
15	4 stars	Yes	No	Yes	5%
16	3 stars	No	Yes	No	5%

Source. Authors run via SPSS.

Table 3.

Sample Choice Set.

Attributes	Dong vermicelli A	Dong vermicelli B	Dong vermicelli C
Star	3 stars	4 stars	I have opted not to select A or B, choosing instead to purchase the items I customarily buy
Traceability	Yes: enough information for traceability	No: not enough information
Wastewater treatment	No	Yes
Residue treatment	No	Yes
Price	15%	20%
Please indicate your preference by selecting a single option	□ Dong vermicelli A	□ Dong vermicelli B	□ Dong vermicelli C

Source. Designed by authors.

Analytical Framework: The Latent Class Model

To analyze consumer preferences and WTP, this study employed the Latent Class Model (LCM), which explicitly accounts for unobserved heterogeneity by assuming that the population consists of a finite number of discrete segments with distinct preference structures (Boxall & Adamowicz, 2002; Greene & Hensher, 2003).

The LCM was selected over alternative discrete choice models for several reasons. In contrast, the Multinomial Logit (MNL) assumes homogeneous preferences across all customers, an unrealistic assumption given the diversity of consumer attitudes toward sustainability and price sensitivity. While the Mixed Logit (MXL) relaxes the homogeneity assumption, it does not explicitly identify discrete consumer segments. The LCM, by contrast, yields clearly interpretable and actionable segments, making it particularly valuable for policy design and marketing strategy (Swait, 1994). These features enable targeted interventions to promote CE-integrated OCOP products, aligning consumer demand with sustainability-oriented certification and rural development objectives.

The LCM is particularly suitable when the research objective is to uncover latent groups (e.g., consumers oriented towards the CE vs. those who are price-sensitive). By jointly estimating class membership probabilities and class-specific utility parameters, the LCM provides a robust statistical framework for preference heterogeneity and actionable insights for targeting consumer segments (Greene & Hensher, 2003). This segmentation capability is especially relevant in the context of CE attributes, where consumers may differ sharply in environmental awareness, trust in certification, and WTP for sustainability practices. By jointly estimating class membership probabilities and class-specific utility parameters, the LCM provides a robust statistical framework for capturing preference heterogeneity while simultaneously linking segment membership to socio-demographic characteristics.

Following Swait (1994), the composite utility function within the latent class model is represented as:

U_{\frac{nj}{k}} = β_{k} X_{jn} + e_{\frac{nj}{k}}

(3)

Here, $U_{nj / k}$ signifies the utility associated with alternative j for individual n, conditional on membership in segment k, within the choice set C.

The probability of a specific consumer (n) belonging to a particular class (k) while choosing alternative (j) can be formulated as follows:

P_{njt} = \sum_{k = 1}^{K} \frac{\exp (β_{k} x_{njt)}}{\sum_{j} \exp (β_{k} x_{njt)}} R_{nk}

(4)

In this equation, $β_{k}$ signifies the parameter vector specifically associated with class k, whereas $R_{nk}$ indicates the probability that consumer n pertains to class k.

The utility function (3) within this investigation is collectively defined as:

\begin{matrix} U_{ni} = β_{1} STA R_{ni} + β_{2} TRAC E_{ni} + β_{3} WWATE R_{ni} \\ + β_{4} RESIDU E_{ni} + β_{5} PRIC E_{ni} + ε_{ni} \end{matrix}

(5)

Where: STAR = product quality rating (3, 4, or 5 stars)

TRACE = traceability code (1 = Yes, 0 = No).

WWATER = wastewater treatment information (1 = Yes, 0 = No).

RESIDUE = residue treatment information (1 = Yes, 0 = No).

PRICE signifies the level of financial expenditure that consumers are willing to pay for a 500 g pack of the Dong vermicelli.

To evaluate consumer preference heterogeneity by extending the basic latent class model, this study modeled prior class membership probabilities as a function of respondents’ socio-demographic characteristics.

P_{jk} = \exp (δ_{k} Z_{n}) / \sum_{J ϵ C} \exp (δ_{k} Z_{n})

(6)

In this context, $P_{jk}$ indicates the probability that a consumer falls into a specific latent segment. The variable $Z_{n}$ encapsulates the n-th respondent’s profile, spanning socio-demographic, attitudinal, and perceptual dimensions, while $δ_{k}$ stands for the parameters requiring estimation. The selected characteristics for this analysis were: AGE (represents a continuous variable that quantifies the age of the respondent in years), INCOME (serves as a continuous variable that quantifies the monthly income of the respondent), AW (serves as a dummy variable that denotes the respondents’ CE awareness), and OCOP (denotes a continuous variable that measures the extent of respondent awareness regarding OCOP products).

To determine the optimal number of segments, the minimization of the Akaike Information Criterion Version 3 (AIC3) is typically employed following the approach recommended by Louviere et al. (2002) for latent class choice models. The AIC3 is formulated as:

AIC 3 = - 2 LL + 3 (S K_{β} + (S - 1) K_{δ})

(7)

In Equation 7: LL is log-likelihood value of the estimated model, representing the goodness-of-fit; S is number of latent classes (segments) in the model; $K_{β}$ is number of parameters in the utility function (β vector) estimated for each class; $K_{δ}$ is number of parameters in the class membership function (δ vector), $S K_{β}$ are utility parameters across S classes, $(S - 1) K_{δ}$ is class membership parameters, with one class serving as reference. The penalty coefficient of 3 (rather than 2 in standard AIC) imposes a stricter penalty appropriate for latent class models prone to overfitting.

The study was conducted with a final sample of 606 participants, with a mean age of 36.66 years (SD = 11.64) and an average monthly income of 19.07 million VND (SD = 7.37 million). The participants were highly aware of the OCOP products (M = 3.97, SD = 0.57). As indicated in Table 4, 45.7% of the participants in this sample demonstrated awareness of the CE concept.

Table 4.

Demographics of Respondents.

Variables	Unit	Mean	SD	Min	Max
Age	Years	36.66	11.64	18	72
Income	Mil. VND/month	19.07	7.37	2	37
CE awareness (AW)	Dummy (1= Yes, 0=No)	0.46	0.49	0	1
OCOP awareness (OCOP)		3.97	0.57	2.5	5

Source. Authors’ calculation from the survey in 2025, n = 606.

The assessment of scale reliability of OCOP awareness, as indicated by Cronbach’s alpha coefficient, obtained a value of 0.762, surpassing the threshold of 0.7, thereby signifying that the scales exhibit a high degree of reliability (George & Mallery, 2019; Hair et al., 2013).

WTP Estimation

Following the estimation of the LCM, the class-specific WTP for each attribute was calculated as the negative ratio of the attribute coefficient to the price coefficient (Hanemann, 1984). This allows for a direct monetary valuation of how much consumers in each identified segment are willing to pay for implementing CE practices and other quality enhancements. The formula used is as follows:

WTP = - \frac{β_{t}}{β_{p}}

(8)

where $β_{t}$ denotes the coefficient representing the part-worth utility of attribute t and $β_{p}$ signifies the coefficient for the part-worth utility of the price attribute.

Data collected were analyzed using SPSS Version 22.0 and NLOGIT Version 5.0.

Results and Discussions

Results

Latent Class Model Results

To determine the optimal number of latent classes, models ranging from one to five classes were systematically evaluated. Although higher-order structures (comprising three to five classes) were explored, these models failed to converge after multiple iterations with different starting values, or produced solutions with one or more classes containing fewer than 5% of respondents -a threshold commonly regarded as indicative of spurious segmentation rather than substantive heterogeneity (Nylund et al., 2007).

The results presented in Table 5 indicate that the two-class specification provides a superior fit compared to the single-class baseline. Specifically, the two-class model yielded the lowest AIC3 value (4,933.5), thereby optimizing the trade-off between model fit and parsimony. Beyond statistical metrics, the two-class solution offers high interpretability, aligning with established theoretical frameworks of consumer segmentation in credence goods markets. The derived segments, comprising a cohort prioritizing sustainability attributes (wastewater treatment, residue treatment, traceability) and a distinct group driven by price and traditional quality signals (star rating), mirror well-documented typologies in food sustainability literature (i.e., “green” versus “conventional” consumers). Furthermore, the cognitive complexity associated with circular economy attributes likely generates a dichotomy in response patterns, which is more accurately captured by two distinct preference structures than by higher-order class solutions. Consequently, the two-class LCM was selected as the most appropriate framework to characterize preference heterogeneity regarding OCOP Dong vermicelli.

Table 5.

Selection Criteria for the Optimal Latent Class Model.

Criteria	Single-class model	Two-class model
Log likelihood (LL)	−2,473.048	−2,447.726
AIC3	4,960.1	4,933.5

Note. Models with 3 to 5 classes were estimated but failed to converge.

Source: Authors’ calculation using Nlogit, the survey in 2025, n = 606.

The likelihood of consumer segmentation is presented in Table 6. The estimated coefficients suggest that Segment 1 is predominantly comprised of individuals with markedly elevated income levels, heightened awareness of the circular economy, and younger demographics. These individuals favor the products’ water conservation and CE practices, including wastewater treatment and residue management, earning them five stars. We classify these individuals as “OCOP Dong vermicelli Advocates.” Conversely, Segment 2, characterized by antithetical perspectives and heightened price sensitivity, is designated as “OCOP Dong vermicelli Skeptics.” These findings highlight the heterogeneity in consumer preferences regarding income, age, and CE awareness. The probability of consumer segmentation was utilized to ascertain the “market share” attributable to each segment (Boxall, 1999; Khai & Yabe, 2015).

Table 6.

Latent Class Model of OCOP Dong Vermicelli.

Segment coefficients
	Seg 1	Seg 2
	OCOP Dong vermicelli advocates	OCOP Dong vermicelli skeptics (values normalized to zero)
Constant	17.4084** (8.64968)	—
Income	0.58595** (0.29403)	—
Age	−0.32183** (0.12711)	—
OCOP awareness (OCOP)	−1.11686 (1.07308)	—
CE awareness (AW)	6.33987** (2.78123)	—

Note. Number of observations 2,424. Values enclosed in parentheses represent standard errors. Statistical significance at the 5% level is indicated by **.

Source. Authors’ calculation using Nlogit, the survey in 2025, n = 606.

Table 7 confirms that price exerts a negative and significant effect on consumer utility in both segments, aligning with the law of demand, whereby higher prices reduce utility and the WTP. This suggests that Dong vermicelli serves as a typical example of a good for Vietnamese consumers. Within this context, “OCOP Dong vermicelli Advocates” exhibit higher WTP for non-price attributes such as sustainability and product quality, whereas “OCOP Dong vermicelli Skeptics” exhibit a lower WTP for these features, reflecting greater price sensitivity.

Table 7.

Utility Functions Coefficients.

Segment coefficients
	Seg 1	Seg 2
	OCOP Dong vermicelli Advocates	OCOP Dong vermicelli Skeptics
Constant	1.13732*** (0.11115)	−5.8283 (0.6098)
Wastewater treatment	0.46439*** (0.09844)	−2.4710 (0.4843)
Residue treatment	0.22197*** (0.05207)	5.9421 (0.6098)
Fourstar	−0.02122 (0.06204)	−1.27784 (1.32508)
Fivestar	0.32342*** (0.07307)	−1.46758 (1.39643)
Traceability	−0.12281 (0.09682)	2.0321 (0.4843)
Price	−4.99483*** (0.55892)	−1.9492** (1.90116)

Note. Statistical significance at the 1% level is indicated by ***.

Source. Authors’ calculation using Nlogit, the survey in 2025, n = 606.

Consumers’ WTP Results

The data presented in Table 8 reveal that consumers identified as “Advocates” are willing to pay a 9.3% premium for OCOP Dong vermicelli when it incorporates wastewater treatment processes. This finding suggests increased awareness among consumers of environmental concerns, encompassing practices aligned with the principles of the circular economy. Furthermore, these consumers demonstrated a higher WTP for residue treatment, valued at an additional 4.4%, signifying a preference for products with environmentally sustainable characteristics. An additional WTP of 6.48% was also evident for products with a five-star rating, suggesting a preference for attributes indicative of quality or recognized standards.

Table 8.

Marginal WTP for OCOP Dong Vermicelli’s Segments.

	Latent class model
	Seg 1	Seg 2
Attributes	OCOP Dong vermicelli Advocates	OCOP Dong vermicelli Skeptics	Multinomial logit
Wastewater treatment	0.093***	1.2677	0.5676***
Residue treatment	0.044***	3.0484	0.23388***
Fourstar	−0.0042	0.6556	−0.02989
Fivestar	0.0648***	0.7529	0.30347***
Traceability	−0.0246	1.0425	−0.11780

Note. The multinomial logit model was utilized to ascertain biases in WTP stemming from heterogeneity.

Significance is denoted by asterisks *** for the 1% level.

Source. Authors’ calculation using Nlogit, the survey in 2025, n = 606.

Discussions

Preference Heterogeneity and Segmentation

This study explores consumer preferences and WTP for the OCOP Dong vermicelli with CE attributes. The results highlight substantial heterogeneity among Vietnamese consumers, suggesting that demand for OCOP products is far from uniform. Demographic and socio-economic differences, consistent with previous evidence (Hong et al., 2025; Trang et al., 2025; Trang & Tu, 2024), play a significant role in shaping choices. For policy and marketing, this means that “one-size-fits-all” strategies are unlikely to succeed. Instead, more tailored approaches are needed to target distinct consumer groups. By demonstrating how heterogeneity interacts with CE attributes, this study provides evidence for designing inclusive and segmented strategies for rural development.

Wastewater Treatment Attribute

Among the CE attributes, wastewater treatment has emerged as particularly valued, with consumers willing to pay a premium of 9.3%. This finding supports prior studies linking wastewater treatment to positive environmental perceptions (Jiao et al., 2024; Munusami et al., 2017; Paola et al., 2018), but contrasts with research showing aversion to the use of recycled water in food (B. Chen et al., 2023; Menegaki et al., 2009). The difference lies in framing: consumers appear more receptive when wastewater treatment is presented as part of responsible production rather than as direct input into consumption. Importantly, income and CE awareness were found to moderate WTP, indicating that outreach campaigns could emphasize environmental stewardship to build support. For policymakers, this suggests that subsidies or certifications tied to wastewater treatment could enhance environmental outcomes and strengthen consumer trust.

Residue Treatment Attribute

Consumers also expressed a WTP a 4.4% premium for residue treatment, reinforcing findings from prior work on recycling and waste treatment (Boyer et al., 2021; Hellali et al., 2023; Pretner et al., 2021; Villanueva et al., 2025). In addition to its environmental benefits, residue management is perceived as a farmer-friendly practice that converts waste into value. This tangibility may explain why consumers reward it as it connects abstract CE principles with visible production improvements. This finding suggests that residue treatment could serve as a focal point for communication, demonstrating both producer responsibility and resource efficiency. Integrating residue treatment into OCOP training programs can support farmers in adopting circular practices that resonate with consumers.

OCOP Star Rating

Consumers were willing to pay 6.48% more for products rated five stars than for those rated four stars, echoing earlier research linking certification to trust and premium pricing (Enneking, 2004; Maesano et al., 2020; Morone et al., 2021; Sriwaranun et al., 2015). Unlike CE attributes, star rating is an immediately visible and government-backed signal, giving consumers confidence in product quality. This highlights the strategic importance of strengthening the credibility of OCOP star systems. More transparent communication of what each star level represents, coupled with strict enforcement of standards, could enhance the value of certification and reinforce the OCOP’s branding in both domestic and export markets.

Traceability Attribute

By contrast, traceability did not generate significant additional WTP. This finding diverges from studies that have identified consumer demand for traceability in food systems (Trang et al., 2025). A possible explanation is that Vietnamese consumers may already assume that OCOP products are trustworthy because of government endorsement, making traceability redundant. Alternatively, visible attributes such as star ratings may crowd out the informational value of the traceability. For marketing purposes, this suggests that investments in traceability technologies may yield limited consumer returns unless they are bundled with other signals. From a policy perspective, the result highlights the contextual nature of consumer trust, while traceability may be critical in export markets or for high-risk products. In local OCOP contexts, more salient attributes, such as certification and environmental practices, should take priority.

Policy Implications

This study shows that Vietnamese consumers are willing to pay premiums for OCOP Dong vermicelli when they incorporate CE attributes such as wastewater treatment and residue management, and achieve a five-star rating under the OCOP program. These findings have several implications for producers, policymakers, and stakeholders.

First, for producers and farmers, the findings suggest that sustainability attributes are not abstract ideals, but marketable qualities that consumers actively recognize and reward. Small investments in low-cost wastewater treatment systems (e.g., settling tanks for water recycling) and the valorization of arrowroot residues into compost, biochar, or livestock feed could simultaneously reduce environmental harm, improve resource efficiency, and create supplementary income streams. However, many small-scale producers face financial and technical constraints, which limit their adoption. Cooperative investment models, shared processing facilities, and access to concessional credit schemes could help to lower these barriers. More broadly, these practices may be transferable to other OCOP and traditional products that face similar environmental pressures. Embedding CE principles into such production systems would contribute to the sustainable development goals related to clean water, responsible consumption, and decent work, aligning local innovation with global sustainability agendas.

Second, for policymakers, the results highlight the importance of enabling frameworks that reward sustainable practices. Fiscal incentives, such as targeted subsidies, concessional loans, and tax reductions, could facilitate the adoption of wastewater treatment and residue management technologies among smallholders. Policymakers might also consider establishing a national standard for sustainable OCOP products and introducing a voluntary “OCOP-Green” or “OCOP-Circular” supplementary label, awarded to producers meeting verifiable criteria for water conservation and waste valorization. Developing clear science-based standards for what constitutes “treated wastewater” or “repurposed residue” would help prevent greenwashing and strengthen consumer confidence. Complementary public awareness campaigns could further educate consumers about the meaning and benefits of sustainability labels, stimulate demand, and reinforce market incentives for certified products. Embedding such measures into rural development programs would not only support Dong vermicelli producers but also create a replicable model for other regions, aligning Vietnam’s rural development strategies with global sustainability commitments.

Third, for marketing and market positioning, the findings indicate that quality assurance and environmental stewardship can be emphasized jointly. Combining five-star OCOP certification with demonstrable CE practices may enable producers to access higher-value domestic and export segments. Producer associations and cooperatives may enhance visibility through certification logos, eco-labels, or QR code traceability systems that connect consumers to authentic production narratives. Digital storytelling, social media engagement, and e-commerce platforms offer particularly promising avenues to reach younger, urban, and higher-income consumers, who often exhibit stronger preferences for sustainability-oriented products.

Finally, beyond Dong vermicelli, these insights point to broader opportunities for scaling. The integration of traditional products with certified CE practices could be extended to other OCOP sectors that face environmental challenges, such as specialty tea (water use), fruit processing (residues), or aquaculture (wastewater). This approach provides a replicable model for developing countries seeking to leverage cultural heritage to create high-value, sustainable products. By co-branding products based on both cultural authenticity and verified environmental stewardship, regions may establish a distinctive market niche that links rural livelihoods with sustainable production and responsible consumption.

Taken together, these policy directions suggest that advancing sustainability within the OCOP framework requires coordinated action among producers, policymakers, and markets. Strengthening synergies among certification, circular-economy practices, and consumer demand could transform traditional local products into drivers of inclusive and environmentally responsible rural development. By aligning incentives, information, and institutional support, Vietnam and similar developing economies may foster a new generation of heritage-based industries in which cultural preservation, environmental stewardship, and market competitiveness reinforce one another.

Limitations and Future Research

Although this study yields valuable insights into consumer preferences and WTP for the OCOP Dong vermicelli, it is crucial to acknowledge certain inherent limitations. First, the dataset was conveniently collected from specific marketplaces in Hanoi. Consequently, the findings may not fully capture the spectrum of consumer preferences across diverse geographical regions or socioeconomic segments in Vietnam. This constraint inherently diminishes the applicability of the findings on the national scale. Additionally, the possibility of social desirability bias cannot be ruled out, as some respondents may have provided answers that they perceived as more socially or environmentally appropriate rather than expressing their valid preferences. Second, the environmental ramifications and implications of the CE were evaluated predominantly through qualitative insights and secondary data, rather than through direct quantification of the environmental impacts or resource utilization efficiencies associated with vermicelli production. Subsequent research endeavors should integrate life cycle assessments and empirical analyses of water consumption and waste management practices to fortify the environmental dimensions of the inquiry. Lastly, the analysis focused on a single OCOP product, which may limit the broader applicability of the findings to other OCOP-certified or traditional food commodities. Extensive comparative investigations encompassing multiple OCOP products and diverse regions would significantly contribute to validating and enhancing these findings.

Footnotes

ORCID iDs

Nguyen Bich Hong

Tran Thi Tuyet

Ethical Considerations

This study was conducted in strict adherence to the ethical guidelines established by the Vietnam National Foundation for Science and Technology Development (NAFOSTED) and Thai Nguyen University of Economics and Business Administration. The research protocol was formally reviewed and approved by the Ethics Review Board (ERB) of Thai Nguyen University of Economics and Business Administration.

Consent to Participate

Informed consent was obtained from all participants prior to their inclusion in the study. Each participant was provided with a comprehensive consent form that detailed the following: an introduction to the study and its objectives, a guarantee of confidentiality, confirmation of the voluntary nature of their participation, and their right to withdraw at any time without consequence. The form also included contact information for the research team and a statement of consent.

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research is funded by the Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 502.01-2021.24.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data Availability Statement

The data and materials supporting this study’s findings are available from the corresponding author, Tran Thi Tuyet, upon reasonable request.

References

Addelman

(1972). Recent developments in the design of factorial experiments. Journal of the American Statistical Association, 67(337), 103–111. https://doi.org/10.1080/01621459.1972.10481211

Alhawari

Awan

Bhutta

M. K. S.

Ülkü

M. A.

(2021). Insights from circular economy literature: A review of extant definitions and unravelling paths to future research. Sustainability, 13(2), Article 2. https://doi.org/10.3390/su13020859

Aminravan

Ahmadi Kaliji

Mulazzani

Rota

Camanzi

(2025). Surveying consumer preferences for eco-labeled fruits and vegetables in Euro-Mediterranean alternative food systems. Frontiers in Sustainable Food Systems, 9, 1576321. https://doi.org/10.3389/fsufs.2025.1576321

Arruda

E. H.

Melatto

R. A. P. B.

Levy

Conti

D. de M.

(2021). Circular economy: A brief literature review (2015–2020). Sustainable Operations and Computers, 2, 79–86. https://doi.org/10.1016/j.susoc.2021.05.001

Awan

Kanwal

Bhutta

M. K. S.

(2020). A literature analysis of definitions for a circular economy. In Golinska-Dawson

(Ed.), Logistics operations and management for recycling and reuse (pp. 19–34). Springer. https://doi.org/10.1007/978-3-642-33857-1_2

Ballco

Gracia

(2022). Tackling nutritional and health claims to disentangle their effects on consumer food choices and behaviour: A systematic review. Food Quality and Preference, 101, 104634. https://doi.org/10.1016/j.foodqual.2022.104634

Barros

M. V.

Salvador

de Francisco

A. C.

Piekarski

C. M.

(2020). Mapping of research lines on circular economy practices in agriculture: From waste to energy. Renewable and Sustainable Energy Reviews, 131, 109958. https://doi.org/10.1016/j.rser.2020.109958

Benatia

M. A.

Baudry

Louis

(2022). Detecting counterfeit products by means of frequent pattern mining. Journal of Ambient Intelligence and Humanized Computing, 13(7), 3683–3692. https://doi.org/10.1007/s12652-020-02237-y

Bhandari

Kumar

Bhatt

Simsek

Kumar

Chaudhary

Malik

Prajapati

S. K.

(2023). An integration of algae-mediated wastewater treatment and resource recovery through anaerobic digestion. Journal of Environmental Management, 342, 118159. https://doi.org/10.1016/j.jenvman.2023.118159

10.

Boxall

P. C.

(1999). Understanding heterogeneous preferences in random utility models: The use of latent class analysis. Department of Rural Economy, Faculty of Agriculture, Forestry and Home Economics, University of Alberta.

11.

Boxall

P. C.

Adamowicz

W. L.

(2002). Understanding heterogeneous preferences in random utility models: A latent class approach. Environmental and Resource Economics, 23, 421–446. https://doi.org/10.1023/A:1021351721619

12.

Boyer

R. H. W.

Hunka

A. D.

Linder

Whalen

K. A.

Habibi

(2021). Product labels for the circular economy: Are customers willing to pay for circular? Sustainable Production and Consumption, 27, 61–71. https://doi.org/10.1016/j.spc.2020.10.010

13.

Campos

D. A.

Gómez-García

Vilas-Boas

A. A.

Madureira

A. R.

Pintado

M. M.

(2020). Management of fruit industrial by-products—A case study on circular economy approach. Molecules, 25(2), Article 2. https://doi.org/10.3390/molecules25020320

14.

Chen

Shi

(2023). Estimating Chinese consumer’s willingness to pay for aquatic food following Japan’s discharge of radioactive wastewater. Aquaculture, 577, 739990. https://doi.org/10.1016/j.aquaculture.2023.739990

15.

Chen

Shang

Zada

Han

Ariza-Montes

Ramírez-Sobrino

(2021). Health is wealth: Study on consumer preferences and the willingness to pay for ecological agricultural product traceability technology: Evidence from Jiangxi Province China. International Journal of Environmental Research and Public Health, 18(22), Article 22. https://doi.org/10.3390/ijerph182211761

16.

Cook

Costa Leite

Rayner

Stoffel

van Rijn

Wollgast

(2023). Consumer interaction with sustainability labelling on food products: A narrative literature review. Nutrients, 15(17), Article 17. https://doi.org/10.3390/nu15173837

17.

Dahlhausen

J. L.

Rungie

Roosen

(2018). Value of labeling credence attributes—Common structures and individual preferences. Agricultural Economics, 49(6), 741–751. https://doi.org/10.1111/agec.12456

18.

Dung

N. T.

Schmied

Van Chinh

(2022). Developing a flexible form of collaborative and inter-organizational governance: The small farmer-focused governance model in Lam San Commune (Vietnam). Global Journal of Flexible Systems Management, 23(1), 51–64. https://doi.org/10.1007/s40171-022-00332-x

19.

Enneking

(2004). Willingness-to-pay for safety improvements in the German meat sector: The case of the Q&S label. European Review of Agricultural Economics, 31, 205–223. https://doi.org/10.1093/ERAE/31.2.205

20.

Fito

Van Hulle

S. W. H.

(2021). Wastewater reclamation and reuse potentials in agriculture: Towards environmental sustainability. Environment, Development and Sustainability, 23(3), 2949–2972. https://doi.org/10.1007/s10668-020-00732-y

21.

Food and Agriculture Organization of the United Nations (FAO). (2022). One commune one product in Viet Nam in regional knowledge platform on one country one priority product (OCOP) in Asia and the Pacific. Retrieved from https://www.fao.org/one-country-one-priority-product/asia-pacific/good-practices/detail/one-commune-one-product-in-viet-nam/en

22.

Garcia-Garcia

Azanedo

Rahimifard

(2021). Embedding sustainability analysis in new food product development. Trends in Food Science & Technology, 108, 236–244. https://doi.org/10.1016/j.tifs.2020.12.018.

23.

Gatti

Gómez

M. I.

Bennett

R. E.

Sillett

T. S.

Bowe

(2022). Eco-labels matter: Coffee consumers value agrochemical-free attributes over biodiversity conservation. Food Quality and Preference, 98, 104509. https://doi.org/10.1016/j.foodqual.2021.104509

24.

Gatti

Gómez

M. I.

Bennett

R. E.

Sillett

Bowe

(2024). Are agrochemical-free and biodiversity-friendly attributes substitutes or complements? Evidence from a coffee choice experiment. Agribusiness. https://doi.org/10.1002/agr.21955

25.

Geisendorf

Pietrulla

(2018). The circular economy and circular economic concepts—A literature analysis and redefinition. Thunderbird International Business Review, 60(5), 771–782. https://doi.org/10.1002/tie.21924

26.

George

Mallery

(2019). IBM SPSS statistics 26 step by step: A simple guide and reference. Routledge.

27.

Gracia

De Magistris

(2008). The demand for organic foods in the South of Italy: A discrete choice model. Food Policy, 33(5), 386–396. https://doi.org/10.1016/j.foodpol.2007.12.002

28.

Greene

W. H.

Hensher

D. A.

(2003). A latent class model for discrete choice analysis: contrasts with mixed logit. Transportation Research Part B: Methodological, 37(8), 681–698. https://doi.org/10.1016/S0191-2615(02)00046-2

29.

Guo

Liao

Liu

Zhang

(2020). Consumer preference analysis: A data-driven multiple criteria approach integrating online information. Omega, 96, 102074. https://doi.org/10.1016/j.omega.2019.05.010

30.

Hair

J. F.

Black

W. C.

Babin

B. J.

Anderson

R. E.

(2013). Multivariate data analysis. Pearson Education Limited.

31.

Hanemann

W. M.

(1984). Welfare evaluations in contingent valuation experiments with discrete responses. American Journal of Agricultural Economics, 66(3), 332-341. https://doi.org/10.2307/1240800

32.

Hanley

Mourato

Wright

R. E.

(2001). Choice modelling approaches: A superior alternative for environmental valuation? Journal of Economic Surveys, 15(3), 435–462. https://doi.org/10.1111/1467-6419.00145

33.

Haque

Fan

Lee

Y. Y.

(2023). From waste to value: Addressing the relevance of waste recovery to agricultural sector in line with circular economy. Journal of Cleaner Production, 415, 137873. https://doi.org/10.1016/j.jclepro.2023.137873

34.

Haraguchi

(2008). The one-village-one-product (OVOP) movement: What it is, how it has been replicated, and recommendations for a UNIDO OVOP-type project. United Nations Industrial Development Organization. https://downloads.unido.org/ot/48/14/4814612/STATISTICS_WP032008%20The%20One-Village-One-Product%20(OVOP)%20movement.pdf

35.

Hellali

Korai

Lambert

(2023). Food from waste: The effect of information and attitude towards risk on consumers’ willingness to pay. Food Quality and Preference, 110, 104945. https://doi.org/10.1016/j.foodqual.2023.104945

36.

Hess

Daly

Batley

(2018). Revisiting consistency with random utility maximisation: theory and implications for practical work. Theory and Decision, 84(2), 181–204. https://doi.org/10.1007/s11238-017-9651-7

37.

Hoang Thanh

Ta Nhat

Nguyen Dang

T. M. H.

Lebailly

(2018). One village one product (OVOP)—A rural development strategy and the early adaption in Vietnam, the case of Quang Ninh Province. Sustainability, 10(12), Article 12. https://doi.org/10.3390/su10124485

38.

Hong

N. B.

Tuyet

T. T.

Linh

D. T. T.

(2025). Consumers’ preferences for Vietnamese OCOP jerky beef: A market driving force for sustainable livestock development and poverty alleviation in the mountainous regions. Discover Sustainability, 6(1), 299. https://doi.org/10.1007/s43621-025-01147-3

39.

Jiao

Yang

Shi

Dogot

Azadi

Yin

(2024). How environmental regulation affects rural residents’ willingness to pay for sustainable domestic sewage treatment: Mediating and interaction effects. Water, 16(5), Article 5. https://doi.org/10.3390/w16050761

40.

Kamboj

Sadh

P. K.

Chawla

Saharan

B. S.

Seth

C. S.

Sridhar

Duhan

J. S.

Sharma

(2024). Sustainable management of rice by-products: Environmental challenges, industrial applications, and circular bio-economy innovations. Biocatalysis and Agricultural Biotechnology, 62, 103430. https://doi.org/10.1016/j.bcab.2024.103430

41.

Khai

H. V.

Yabe

(2015). Consumer preferences for agricultural products considering the value of biodiversity conservation in the Mekong Delta, Vietnam. Journal for Nature Conservation, 25, 62–71. https://doi.org/10.1016/j.jnc.2015.02.004

42.

Knight

(1994). Rural revitalization in Japan: Spirit of the village and taste of the country. Asian Survey, 34(7), 634–646. https://doi.org/10.2307/2645373

43.

Kuenne

R. E.

(1998). Characteristics as objects of consumer preference. In Price and nonprice rivalry in oligopoly: The integrated battleground (pp. 105–126). Palgrave Macmillan.

44.

Kurniawan

S. B.

Ahmad

Said

N. S. M.

Imron

M. F.

Abdullah

S. R. S.

Othman

A. R.

Purwanti

I. F.

Hasan

H. A.

(2021). Macrophytes as wastewater treatment agents: Nutrient uptake and potential of produced biomass utilization toward circular economy initiatives. Science of the Total Environment, 790, 148219. https://doi.org/10.1016/j.scitotenv.2021.148219

45.

Kurokawa

(2009). Effectiveness and limitations of the ‘one village one product’ (OVOP) approach as a government-led development policy: Evidence from Thai ‘one tambon one product’ (OTOP). 地域学研究, 39(4), 977–989. https://doi.org/10.2457/srs.39.977

46.

Kušar

Pravst

Pivk Kupirovič

Grunert

K. G.

Kreft

Hristov

(2023). Consumers’ preferences towards bread characteristics based on food-related lifestyles: insights from Slovenia. Foods, 12(20), 3766. https://doi.org/10.3390/foods12203766

47.

Kallas

(2021). Meta-analysis of consumers’ willingness to pay for sustainable food products. Appetite, 163. https://doi.org/10.1016/j.appet.2021.105239

48.

Liu

C. C.

Chen

C. W.

Chen

H. S.

(2019). Measuring consumer preferences and willingness to pay for coffee certification labels in Taiwan. Sustainability, 11(5), 1297. https://doi.org/10.3390/su11051297

49.

Lizin

Rousseau

Kessels

Meulders

Pepermans

Speelman

Vandebroek

Van Den Broeck

Van Loo

E. J.

Verbeke

(2022). The state of the art of discrete choice experiments in food research. Food Quality and Preference, 102, 104678. https://doi.org/10.1016/j.foodqual.2022.104678

50.

López-Sánchez

Silva-Gálvez

A. L.

Aguilar-Juárez

Ó.

Senés-Guerrero

Orozco-Nunnelly

D. A.

Carrillo-Nieves

Gradilla-Hernández

M. S.

(2022). Microalgae-based livestock wastewater treatment (MbWT) as a circular bioeconomy approach: Enhancement of biomass productivity, pollutant removal and high-value compound production. Journal of Environmental Management, 308, 114612. https://doi.org/10.1016/j.jenvman.2022.114612

51.

Louviere

Street

Carson

Ainslie

DeShazo

J. R.

Cameron

Hensher

Kohn

Marley

(2002). Dissecting the random component of utility. Marketing Letters, 13(3), 177–193. https://doi.org/10.1023/A:1020258402210

52.

Louviere

J. J.

(1992). Experimental choice analysis: Introduction and overview. Journal of Business Research, 24(2), 89–95. https://doi.org/10.1016/0148-2963(92)90054-F

53.

Louviere

J. J.

Hensher

D. A.

Swait

J. D.

(2000). Stated choice methods: Analysis and Applications. Cambridge University Press.

54.

Lusk

J. L.

Schroeder

T. C.

(2004). Are choice experiments incentive compatible? A test with quality differentiated beef steaks. American Journal of Agricultural Economics, 86(2), 467–482. https://doi.org/10.1111/j.0092-5853.2004.00592.x

55.

Maaya

Meulders

Surmont

Vandebroek

(2018). Effect of environmental and altruistic attitudes on willingness-to-pay for organic and fair trade coffee in Flanders. Sustainability, 10(12), 4496. https://doi.org/10.3390/su10124496

56.

Maesano

Di Vita

Chinnici

Pappalardo

D’Amico

(2020). The role of credence attributes in consumer choices of sustainable fish products: A review. Sustainability, 12(23), Article 23. https://doi.org/10.3390/su122310008

57.

Mannina

Gulhan

B.-J.

(2022). Water reuse from wastewater treatment: The transition towards circular economy in the water sector. Bioresource Technology, 363, 127951. https://doi.org/10.1016/j.biortech.2022.127951

58.

Mas-Colell

Whinston

M. D.

Green

J. R.

(1995). Microeconomic theory (Vol. 1). New York: Oxford University Press.

59.

McFadden

Train

(2000). Mixed MNL models for discrete response. Journal of applied Econometrics, 15(5), 447-470. https://doi.org/10.1002/1099-1255(200009/10)15:5%3C447::AID-JAE570%3E3.0.CO;2-1

60.

Menegaki

A. N.

Mellon

R. C.

Vrentzou

Koumakis

Tsagarakis

K. P.

(2009). What’s in a name: Framing treated wastewater as recycled water increases willingness to use and willingness to pay. Journal of Economic Psychology, 30(3), 285–292. https://doi.org/10.1016/j.joep.2008.08.007

61.

Mesidis

Lockshin

Corsi

A. M.

Page

Cohen

(2023). Measuring the effect of product and environmental messaging attributes on alternative wine packaging choices. Journal of Cleaner Production, 431, 139502. https://doi.org/10.1016/j.jclepro.2023.139502

62.

Morone

Caferra

D’Adamo

Falcone

P. M.

Imbert

Morone

(2021). Consumer willingness to pay for bio-based products: Do certifications matter? International Journal of Production Economics, 240, 108248. https://doi.org/10.1016/j.ijpe.2021.108248

63.

Morseletto

Mooren

C. E.

Munaretto

(2022). Circular Economy of Water: Definition, Strategies and Challenges. Circular Economy and Sustainability, 2(4), 1463–1477. https://doi.org/10.1007/s43615-022-00165-x

64.

Munusami

Othman

Mohamad Ismail

Siwar

(2017). Estimation of willingness to pay for wastewater treatment service improvement in Malaysia. International Journal of Business and Society, 17(2), 365–374. https://doi.org/10.33736/ijbs.530.2016

65.

Murray

Skene

Haynes

(2017). The circular economy: An interdisciplinary exploration of the concept and application in a global context. Journal of Business Ethics, 140(3), 369–380. https://doi.org/10.1007/s10551-015-2693-2

66.

Newman

Singhal

Tarp

(2020). Introduction to understanding agricultural development and change: Learning from Vietnam. Food Policy, 94, 101930. https://doi.org/10.1016/j.foodpol.2020.101930

67.

Nguyen

H. Q.

Korbee

H. L.

Weger

Phan

T. T. H.

Nguyen

T. T. D.

Pham

D. M. H. L.

Luu

T. T.

Dang

H. P. T.

Ngo

T. T. T.

Hermans

Evers

Wyatt

Nguyen

C. X. Q.

P. L.

(2019). Farmer adoptability for livelihood transformations in the Mekong Delta: A case in Ben Tre province. Journal of Environmental Planning and Management, 62(9), 1603–1618. https://doi.org/10.1080/09640568.2019.1568768

68.

Nguyen

P. B. N.

Pham

V. T.

Viet Le

Kumar

Meraj

(2024). Pollution mitigation in vermicelli wastewater: Integrated Fenton and aerobic sludge treatment for water quality improvement. Scientifica, 2024(1), 8133617. https://doi.org/10.1155/2024/8133617

69.

Nylund

K. L.

Asparouhov

Muthén

B. O.

(2007). Deciding on the number of classes in latent class analysis and growth mixture modeling: A Monte Carlo simulation study. Structural Equation Modeling: A Multidisciplinary Journal, 14(4), 535–569. https://doi.org/10.1080/10705510701575396

70.

Orme

B. K.

(2010). Getting Started with Conjoint Analysis: Strategies for Product Design and Pricing Research. Research Publishers.

71.

Paola

Mustafa

A. A.

Giacomo

(2018). Willingness to pay for recreational benefit evaluation in a wastewater reuse project. Analysis of a case study. Water, 10(7), Article 7. https://doi.org/10.3390/w10070922

72.

Perdue

Milkman

Marcis

(2013). The OVOP strategy as Guam’s choice to improve the tourism industry. Journal of Economics and Economic Education Research, 14(3), 28–33.

73.

Pham

T. T. O.

(2020). Quản lý nước thải sản xuất miến tại làng nghề Đông Thọ, Thái Bình, Việt Nam. Tạp chí Khí tượng Thủy văn, 225(2), 99–103. https://doi.org/10.34238/tnu-jst.2020.02.2699

74.

Phi

T. H. L.

Bui

T. T. H.

(2022). Sustainable agriculture development in Vietnam. In Nguyen

A. T.

Hens

(Eds.), Global changes and sustainable development in Asian emerging market economies Vol. 2: Proceedings of EDESUS 2019 (pp. 207–223). Springer International Publishing. https://doi.org/10.1007/978-3-030-81443-4_14

75.

Pretner

Darnall

Testa

Iraldo

(2021). Are consumers willing to pay for circular products? The role of recycled and second-hand attributes, messaging, and third-party certification. Resources, Conservation and Recycling, 175, 105888. https://doi.org/10.1016/j.resconrec.2021.105888

76.

Prieto-Sandoval

Jaca

Ormazabal

(2018). Towards a consensus on the circular economy. Journal of Cleaner Production, 179, 605–615. https://doi.org/10.1016/j.jclepro.2017.12.224

77.

Priyadharshini

S. D.

Babu

P. S.

Manikandan

Subbaiya

Govarthanan

Karmegam

(2021). Phycoremediation of wastewater for pollutant removal: a green approach to environmental protection and long-term remediation. Environmental Pollution, 290, 117989. https://doi.org/10.1016/j.envpol.2021.117989

78.

Xiao

Upadhyay

Luo

(2024). Perspectives on sustainable food production system: Characteristics and green technologies. Journal of Agriculture and Food Research, 15, 100988. https://doi.org/10.1016/j.jafr.2024.100988

79.

Rodias

Aivazidou

Achillas

Aidonis

Bochtis

(2021). Water-energy-nutrients synergies in the agrifood sector: A circular economy framework. Energies, 14(1), Article 1. https://doi.org/10.3390/en14010159

80.

Rodríguez-Espinosa

Papamichael

Voukkali

Gimeno

A. P.

Candel

M. B. A.

Navarro-Pedreño

Zorpas

A. A.

Lucas

I. G.

(2023). Nitrogen management in farming systems under the use of agricultural wastes and circular economy. Science of the Total Environment, 876, 162666. https://doi.org/10.1016/j.scitotenv.2023.162666

81.

Ruiz-Pastor

Mesa

J. A.

(2023). Proposing an integrated indicator to measure product repairability. Journal of Cleaner Production, 395, 136434. https://doi.org/10.1016/j.jclepro.2023.136434

82.

Sama

Crespo-Cebada

Díaz-Caro

Escribano

Mesías

F. J.

(2018). Consumer preferences for foodstuffs produced in a socio-environmentally responsible manner: A threat to fair trade producers? Ecological Economics, 150, 290–296. https://doi.org/10.1016/j.ecolecon.2018.04.031

83.

Sánchez-Bravo

Chambers

V, E.

Noguera-Artiaga

Sendra

Chambers

IV, E.

Carbonell-Barrachina

Á. A.

(2021). Consumer understanding of sustainability concept in agricultural products. Food Quality and Preference, 89, 104136. https://doi.org/10.1016/j.foodqual.2020.104136

84.

Shahid

Malik

Zhu

Nawaz

M. Z.

Nawaz

Alam

M. A.

Mehmood

M. A.

(2020). Cultivating microalgae in wastewater for biomass production, pollutant removal, and atmospheric carbon mitigation: A review. Science of the Total Environment, 704, 135303. https://doi.org/10.1016/j.scitotenv.2019.135303

85.

Silva

J. A.

(2023). Wastewater treatment and reuse for sustainable water resources management: A systematic literature review. Sustainability, 15(14), Article 14. https://doi.org/10.3390/su151410940

86.

Snowball

J. D.

Willis

K. G.

(2006). Estimating the marginal utility of different sections of an arts festival: The case of visitors to the South African National Arts Festival. Leisure Studies, 25(1), 43–56. https://doi.org/10.1080/0261436052000330410

87.

Sohrabi

Pishvaee

M. S.

Hafezalkotob

Bamdad

(2020). A multi-attribute model to optimize the price and composition of prepaid mobile Internet plans. Journal of Enterprise Information Management, 33(5), 1257–1291. https://doi.org/10.1108/JEIM-09-2019-0279

88.

Sriwaranun

Gan

Lee

Cohen

D. A.

(2015). Consumers’ willingness to pay for organic products in Thailand. International Journal of Social Economics, 42(5), 480–510. https://doi.org/10.1108/IJSE-09-2013-0204

89.

(2021). Revisiting carbon, nitrogen, and phosphorus metabolisms in microalgae for wastewater treatment. Science of the Total Environment, 762, 144590. https://doi.org/10.1016/j.scitotenv.2020.144590

90.

H. A.

Faminow

M. D.

Johnson

G. V.

Crow

(1997). Estimating the values of cattle characteristics using an ordered probit model. American Journal of Agricultural Economics, 79(2), 463–476. https://doi.org/10.2307/1244144

91.

Swait

(1994). A structural equation model of latent segmentation and product choice for cross-sectional revealed preference choice data. Journal of Retailing and Consumer Services, 1(2), 77–89. https://doi.org/10.1016/0969-6989(94)90002-7

92.

Tait

Saunders

Dalziel

Rutherford

Driver

Guenther

(2019). Estimating wine consumer preferences for sustainability attributes: A discrete choice experiment of Californian Sauvignon blanc purchasers. Journal of Cleaner Production, 233, 412–420. https://doi.org/10.1016/j.jclepro.2019.06.076

93.

Tienhaara

Ahtiainen

Pouta

(2015). Consumer and citizen roles and motives in the valuation of agricultural genetic resources in Finland. Ecological Economics, 114, 1–10. https://doi.org/10.1016/j.ecolecon.2015.03.005

94.

Torma

Thøgersen

(2024). Can a meta sustainability label facilitate more sustainable consumer choices? Business Strategy and the Environment, 33(2), 283–306. https://doi.org/10.1002/bse.3488

95.

Tran

D. D.

Huu

L. H.

Hoang

L. P.

Pham

T. D.

Nguyen

A. H.

(2021). Sustainability of rice-based livelihoods in the upper floodplains of Vietnamese Mekong Delta: Prospects and challenges. Agricultural Water Management, 243, 106495. https://doi.org/10.1016/j.agwat.2020.106495

96.

Trang

N. T.

Kopp

S. W.

V. H.

(2025). Sustainable development of local livelihoods in Vietnam: A demand-driven approach through “One Commune, One Product.” Sustainable Development, 33(1), 270–286. https://doi.org/10.1002/sd.3118

97.

Trang

N. T.

V. H.

(2024). A consumer-driven approach to the development of OCOP beverage products in Hau Giang Province. Journal of Positive Psychology and Wellbeing, 8(1), 15–35. https://journalppw.com/index.php/jppw/article/view/17954

98.

V. H.

Kopp

S. W.

Trang

N. T.

Kontoleon

Yabe

(2021). UK consumers’ preferences for ethical attributes of floating rice: Implications for environmentally friendly agriculture in Vietnam. Sustainability, 13(15), Article 15. https://doi.org/10.3390/su13158354

99.

Villanueva

A. J.

Salazar-Ordóñez

Granado-Díaz

(2025). Consumer preferences toward new circular bioeconomy agri-food products. Sustainable Development, 33(2), 2614–2633. https://doi.org/10.1002/sd.3239

100.

Velasco-Muñoz

J. F.

Aznar-Sánchez

J. A.

López-Felices

Román-Sánchez

I. M.

(2022). Circular economy in agriculture. An analysis of the state of research based on the life cycle. Sustainable Production and Consumption, 34, 257–270. https://doi.org/10.1016/j.spc.2022.09.017

101.

Wierenga

(1984). Empirical test of the Lancaster characteristics model. International Journal of Research in Marketing, 1(4), 263–293.

102.

Wang

Zhu

Wang

(2015). Chinese consumers’ preferences and willingness to pay for traceable food quality and safety attributes: The case of pork. China Economic Review, 35, 121–136. https://doi.org/10.1016/j.chieco.2015.07.001

103.

Zhang

van Klinken

R. D.

Schrobback

Muller

J. M.

(2021). Consumer trust in food and the food system: A critical review. Foods, 10(10), Article 10. https://doi.org/10.3390/foods10102490

104.

Yin

Chen

Wang

(2017). Consumer preference and willingness to pay for the traceability information attribute of infant milk formula: Evidence from a choice experiment in China. British Food Journal, 119(6), 1276–1288. https://doi.org/10.1108/BFJ-11-2016-0555

105.

Zhu

Guo

Ren

(2022). Consumer preference analysis based on text comments and ratings: A multi-attribute decision-making perspective. Information & Management, 59(3), 103626. https://doi.org/10.1016/j.im.2022.103626