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Conjoint analysis has become popular
among social scientists for measuring multidimensional preferences.
When analyzing such experiments, researchers often focus on the
average marginal component effect (AMCE), which represents the
causal effect of a single profile attribute while averaging over the
remaining attributes. What has been overlooked, however, is the
fact that the AMCE critically relies upon the distribution of the
other attributes used for the averaging. Although most experiments
employ the uniform distribution, which equally weights each profile,
both the actual distribution of profiles in the real world and the
distribution of theoretical interest are often far from uniform.
This mismatch can severely compromise the external validity of
conjoint analysis. We empirically demonstrate that estimates of the
AMCE can be substantially different when averaging over the target
profile distribution instead of uniform. We propose new experimental
designs and estimation methods that incorporate substantive
knowledge about the profile distribution. We illustrate our
methodology through two empirical applications, one using a
real-world distribution and the other based on a counterfactual
distribution motivated by a theoretical consideration. The proposed
methodology is implemented through an open-source software
package. |
Egami, Naoki, Brandon de la Cuesta, and
Kosuke Imai. ``factorEx:
Design and Analysis for Factorial Experiments.''
available through The Comprehensive
R Archive Network and GitHub. |
Egami, Naoki, and Kosuke
Imai. (2019). ``Causal Interaction in
Factorial Experiments: Application to Conjoint
Analysis.'' Journal of the American Statistical
Association, Vol. 114, No. 526 (June), pp. 529-540.
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Goplerud, Max, Kosuke Imai, Nicole E. Pashley. ``Estimating Heterogeneous Causal
Effects of High-Dimensional Treatments: Application to Conjoint
Analysis.'' |
Ham, Dae Woong, Kosuke Imai, and Lucas
Janson. ``Using Machine Learning to
Test Causal Hypotheses in Conjoint Analysis.''
Political Analysis, Forthcoming. |