Inferring individual preferences from group decisions: judicial preference variation and aggregation in asylum appeals

While many democracies nominate partisan judges, empirical research has struggled to assess whether such judges adhere to Aristotle’s maxim that like cases should be treated alike. One fundamental problem hindering empirical research is that many courts only report decisions of panels, not the opinions of individual judges. We propose a methodology that tests which of several decision-theoretic models of group decision-making best fit the panel decisions, infers judges’ individual preferences, and quantifies the proportion of cases that would be decided differently if the courts’ consensus were consistently applied (an inconsistency rate). Applying this methodology to the Swiss asylum appeal process, where cases are assigned conditionally at random and have a common, unidimensional structure, we find a persistent inconsistency rate of about 5% due to variation in decision-making between judges, and that judges’ estimated preferences are correlated with party membership in expected ways