A closer examination of three small-sample approximations to the multiple-imputation degrees of freedom,erratum

Abstract

In the print and electronic versions of Wagstaff and Harel (2011, Stata Journal 11: 403–419), the equation at the bottom of page 405 appeared as

v_{L P Z} = \frac{{[\bar{W} + {(m + 1) / m} B]}^{2}}{{{\bar{W}}^{2} / N - 1} + {(m + 1) m}^{2} {B^{2} / (m - 1)}}

but should have appeared as

v_{L P Z} = \frac{{[\bar{W} + {(m + 1) / m} B]}^{2}}{{{\bar{W}}^{2} / (N - 1)} + {(m + 1) / m}^{2} {B^{2} / (m - 1)}}

That is, the formula should read ${(m + 1) / m}^{2}$ and not ${(m + 1) m}^{2}$ in the denominator. The erroneous expression was not used in the simulation, so the results stand.

Footnotes

Announcements

References

Wagstaff

D. A.

Harel

2011. A closer examination of three small-sample approximations to the multiple-imputation degrees of freedom. Stata Journal 11: 403–419.