2026 General Seminar no. 5 - Xiaodong Gong (Canberra)

Title: Overcoming Reflection: A Panel data approach to Judicial Peer effects

by Xiaodong Gong and Benoit Pierre Freyens

Abstract: We propose an identification strategy that directly addresses the reflection problem in peer effects models. We illustrate by examining how peer effects shape individual judges’ decisions in labour disputes. Using a rich multi-level panel dataset covering more than 2,000 rulings over a 16-year period, we identify these effects by leveraging the random assignment of cases to judges and the precise sequencing of case filings and decisions. This allows us to address the simultaneity (or reflection) problem that complicates the identification of peer effects in standard models. The depth of the data also enables us to explore the underlying sources of these peer effects. Our findings reveal heterogeneous and asymmetric endogenous (behavioural) peer effects, with the magnitude and direction of influence varying across judge types.