I detect intra-judge variation in judicial decisions driven by factors completely unrelated 5 to the merits of the case, or to any case characteristic for that matter. Concretely, I show that asylum 6 grant rates in U.S. immigration courts differ by the success of the court city’s NFL team on the night 7 before, and by the city’s weather on the day of, the decision. My data including half a million decisions 8 spanning two decades allows me to exclude confounding factors, such as scheduling and seasonal effects. 9 Most importantly, my design holds the identity of the judge constant. On average, U.S. immigration 10 judges grant an additional 1.5% of asylum petitions on the day after their city’s NFL team won, relative 11 to days after the team lost. Bad weather on the day of the decision has approximately the opposite effect. 12 By way of comparison, the average grant rate is 39%. In contrast, I do not find comparable effects in 13 sentencing decisions of U.S. District Courts, and speculate that this may be due to higher quality of the 14 federal judges, more time for deliberation, or the constraining effect of the federal sentencing guidelines.
TSE Working Paper, n° 16-707, septembre 2016, révision février 2017