Pay to Perform? Causal Evidence from a Randomized Field Experiment in Tanzanian Football

This paper examines the causal effect of financial incentives on performance in a football training setting. We conducted a randomized field experiment between May and June 2025 involving 301 football players from the first three leagues in Tanzania. The players were assigned to either a control group without incentives or a treatment group in which we paid performance-contingent rewards. Participants completed five standardized tasks, covering effort-based and skill-based performance. Seemingly unrelated regressions show that incentivized players performed significantly better in effort-based tasks, characterized by faster sprint times and higher endurance scores. In skill-based tasks, no differences in accuracy were found between the groups, though pass execution was significantly faster in the incentive condition. The results suggest that financial incentives are effective in increasing physical effort but have limited influence on skill-based tasks. The findings have practical relevance for designing compensation schemes that align incentives with observable and effort-based performance.