Ethnic Bias in Judicial Decision Making: Evidence from Criminal Appeals in Kenya

Abstract

Understanding sources of judicial bias is essential for establishing due process. To date, theories of judicial decision making are rooted in ranked societies with majority–minority group cleavages, leaving unanswered which groups are more prone to express bias and whether it is motivated by in-group favoritism or out-group hostility. We examine judicial bias in Kenya, a diverse society that features a more complex ethnic landscape. While research in comparative and African politics emphasizes instrumental motivations underpinning ethnic identity, we examine the psychological, implicit biases driving judicial outcomes. Using data from Kenyan criminal appeals and the conditional random assignment of judges to cases, we show that judges are 3 to 5 percentage points more likely to grant coethnic appeals than non-coethnic appeals. To understand mechanisms, we use word embeddings to analyze the sentiment of written judgments. Judges use more trust-related terms writing for coethnics, suggesting that in-group favoritism motivates coethnic bias in this context.

Judicial Decision-Making. A Survey of the Experimental Evidence

“…Even if decision makers are motivated to be impartial, bias may sneak in inadvertently. This has been demonstrated for race (Rachlinski, Johnson et al 2008) and ethnicity (Gazal-Ayal and Sulitzeanu-Kenan 2010, Choi, Harris et al 2022), gender (Kulik, Perry et al 2003, Miller 2019, ideology (Furgeson, Babcock et al 2008) or induced punishment philosophy (McFatter 1978), and for the stereotype that tattoos are typical for criminals, and hence predict guilt (Funk and Todorov 2013). Legal education mitigates the effect of stereotypes, but only if the learned rules are simple, rather than judgmental -rules, rather than standards, in the terminology often used in law and economics (Girvan 2016).…”