Do Judges Cherry Pick Precedents to Justify Extra- Legal Decisions?: a Statistical Examination

Abstract

Do judges simply cherry pick precedents to justify decisions that reflect their personal biases rather than the weight of legal authority? Legal realists and legal skeptics have contended that judges use case law as a means of justifying decisions that have been made extra-legally. We test this hypothesis by statistically analyzing the citation practices of California Court of Appeal judges in unconscionable contract cases. We reject the claims of the legal realists and legal skeptics, finding no evidence that judges manipulate the existing case law by selecting favorable precedents to justify extra-legal decisions. Judges writing pro-plaintiff opinions are more likely to cite pro-plaintiff precedents; and pro-defendant opinions are more likely to cite pro-defendant precedents. While this is consistent with the idea that judges cherry pick precedents to cite in order to justify their decisions, it is also consistent with the idea that the precedents that are cited in a legal opinion are the most influential. To determine the direction of causation, we use a new methodology for analyzing the use of precedents in legal opinions, exploiting the fact that decisions correlate with perceived political preferences in the area of law we investigate. Citations of precedent in cases where judges vote in accordance with their perceived political preference do not significantly differ from citations of precedent in cases where judges do not vote in line with their perceived political preference. This is evidence that judges do not simply cherry pick precedents when writing opinions.