Political Identity and Conjunction Fallacy: Experimental Evidence from the 2024 U.S. Presidential Election

In the context of the 2024 U.S. presidential election, experimental participants evaluate lotteries based on electoral outcomes (Trump or Harris winning), economic outcomes (improvement or decline), and the conjunctions of these outcomes. We document a conjunction fallacy in choices: participants value lotteries on conjunctive events more than single events. This pattern is stronger when conjunctive outcomes are congruent with participants’ partisan identities—for example, a Harris victory combined with improved economic condition for Democrats—than when they are incongruent. Our results challenge models that satisfy dominance and point to preference-based explanations encompassing the source and the valence of uncertainty.