Affirmation Bias? Supreme Court Decision-Making in the Circuit-Riding Century

Abstract: This article quantitatively analyzes the effect of circuit riding on judicial decision-making, particularly affirmation rates. From 1790 to 1891, the Supreme Court Justices served as circuit judges as well as Justices, a system that allowed for the possibility of the Justices reviewing their own circuit opinions on appeal to the Supreme Court. Despite encapsulating the formative period of the Court, the “Circuit-Riding Century” is understudied in the literature, and there is a dearth of materials relating to the practice. I introduce three theoretical explanations for the effect of circuit riding on Supreme Court affirmation rates: the circuit Justice’s fear of reversal by his brethren, protecting the legitimacy of the Court, and the circuit Justice as an advocate. All three explanations lead to the same hypothesis: cases heard by Justices on circuit were more likely to be affirmed by the Supreme Court than cases that do not feature a Justice. In order to test my hypothesis, I constructed two groups, the experiment group (containing cases heard by Justices on the circuit level) and the control group (consisting of cases from state courts and the D.C. Circuit, which did not have a Justice assigned) in order to do a Welch’s t-test on the difference of affirmation rates between the two groups. I then used three case studies to elucidate my theoretical explanations. Though the difference between affirmation rates is not statistically significant, this thesis is the first study to provide a concrete, positive answer to the speculated effect of circuit riding on Supreme Court decision-making.

Author: Will Giles graduated from Duke University in 2015 with a B.A. in Political Science.

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