Preference stability and choice consistency in discrete choice experiments

© 2015, Springer Science+Business Media Dordrecht.We investigate preference stability and respondents’ levels of choice consistency within discrete choice experiments. These are investigated via a discrete choice experiment featuring four information treatments and a retest survey completed 6 months after the first. Three information treatments concern a novel, stem cell, food technology with the fourth information treatment featuring a non-novel technology. We find stable welfare estimates over the three information treatments; the use of emotive keywords does not systematically change WTP to avoid the stem cell food technology. We find a significant WTP to avoid the non-novel technology. We find high levels of intertemporal preference stability and choice consistency. The determinants of choice consistency are examined. Two factors are significant: a measure of the choice task’s complexity (entropy) and a novel measure of respondents’ cognitive capability, derived within the survey. We find a significant selection issue, not previously identified in discrete choice experiment test–retest studies, with those opting to take the retest exhibiting greater choice consistency in the initial survey. This suggests that studies which report high levels of test–retest choice consistency, without accounting for the selection issue, are overstating population choice consistency.