The impact of temperature on labor quality: Umpire accuracy in Major League Baseball

• Main Author: FESSELMEYER, Eric
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2021
• Subjects: heat stress; labor productivity; labor quality; temperature; Labor Economics; Work, Economy and Organizations
• Online Access: https://ink.library.smu.edu.sg/cis_research_all/9; https://ink.library.smu.edu.sg/context/cis_research_all/article/1008/viewcontent/Southern_Economic_Journal___2021___Fesselmeyer___The_impact_of_temperature_on_labor_quality__Umpire_accuracy_in_Major.pdf
• Institution: Singapore Management University

Using data from Major League Baseball, I compute an objective measure of the home plate umpire's work quality-the accuracy of his ball and strike calls during a game-and measure how it varies with temperature. I find that an increase in game-time temperature from between 70 and 80 degrees F to above 95 degrees F decreases an umpire's accuracy by a little less than a percentage point, which is a 5.5% increase in the pitch-calling error rate when evaluated at the mean error rate of 13.3%. Restricting the sample to borderline pitches increases the magnitude of the hot-weather effect on accuracy to over a percentage point. My results indicate that very hot temperatures have a nontrivial, negative effect on the labor supply quality of a highly trained and highly skilled workforce in an important, high-revenue, and high-stakes industry, and suggest that protecting workers from daily variation in temperature can improve labor productivity.