Framing Effects in Proportionality Analysis: Experimental Evidence

Proportionality Analysis (PA) is usually perceived as applying a rationality-based formula to determine whether a legal act is (un)constitutional. However, behavioral economics suggests that decisionmakers—including judges—may be susceptible to various cognitive biases, which implies that PA might be similarly affected. Using a vignette experiment, we examine how different framings of legal cases influence PA judgments across three groups: administrative judges, law students, and non-law students. Results show that judges demonstrate minimal susceptibility to framing effects when conducting PA, suggesting that legal expertise and professional experience can provide significant protection against cognitive biases in judicial decision-making. These findings provide reassuring evidence for the rationality of PA as applied by professional judges, while demonstrating the debiasing impact of legal training and expertise. However, we also find that judges remain susceptible to other behavioral effects when making decisions that are unrelated to PA. We discuss the relevance of our findings for the current debate surrounding constitutional review, contrasting PA—used frequently around the globe—with the specific constitutional review process in the United States.