What Do We Learn About Voter Preferences From Conjoint Experiments?

• In Event: Advances in Experimental Methods and Designs Across the Subfields

Abstract

Political scientists frequently interpret the results of conjoint experiments as reflective of voter preferences. In this paper we show that the target estimand of conjoint experiments, the AMCE, is not well-defined in these terms. Even with individually rational experimental subjects, unbiased estimates of the AMCE can indicate the opposite of the true preference of the majority. To show this, we characterize the preference aggregation rule implied by AMCE and demonstrate its several undesirable properties. With this result we provide a method for placing sharp bounds on the proportion of experimental subjects with a strict preference for a given candidate-feature. We provide a testable assumption to show when the AMCE corresponds in sign with the majority preference. Finally, we offer a structural interpretation of the AMCE and highlight that the problem we describe persists even when a model of voting is imposed.

Authors

• Asya Magazinnik, MIT

• Scott Abramson, University of Rochester

• Korhan Kocak, New York University Abu Dhabi