Jc. Whitehead, ITEM NONRESPONSE IN CONTINGENT VALUATION - SHOULD CV RESEARCHERS IMPUTE VALUES FOR MISSING INDEPENDENT VARIABLES, Journal of leisure research, 26(3), 1994, pp. 296-303
Item nonresponse is a common problem in contingent valuation research.
Discarding incomplete cases will result in biased samples if the disc
arded cases are nonrandom. Imputing values for missing independent var
iables and including the incomplete cases may improve overall economet
ric performance, correct sample bias, and correct bias in aggregate be
nefit estimates.