Risk-taking and performance in marathon running: do pace setters matter?

After many years of using pace setters, the Chicago Marathon eliminated professional pacers for elite runners for the 2015, 2016, and 2017 races, and then reinstated the use of pace setters beginning with the 2018 race. Publicly available data was collected pertaining to the three Chicago Marathon races that did not use pace setters and for the three races subsequent to the reinstatement of pacers. For the same years, data was also collected for the New York Marathon, a World Majors Marathon that did not use professional pace setters for elite runners in any race years under consideration. Difference-in-differences estimations were used to determine the impacts of professional pace setters on the performance of elite male marathon runners. Results indicate that use of professional pacers does improve the race times of the fastest elite runners while making the race appear less competitive by creating more separation between the runners earlier in the race.