The effect of rivalry on performance and sabotage: evidence from the national football league

Competitive rivalry is a central driver of behavior and market outcomes, yet its effects on performance and unethical conduct remain insufficiently understood. Drawing on data from the National Football League (2009–2023) and a survey-based measure of rivalry, this study investigates how perceived rivalry in the competition influences performance and sabotage behavior. Using team fixed effects estimations, we find that especially symmetrical rivalry impairs performance, whereas performance improves when the opponent rates the rivalry higher. Moreover, we identify a u-shaped relationship between rivalry intensity and sabotage fouls: sabotage is lowest at moderate rivalry levels but increases under both low and high rivalry. Overall, our findings indicate that contests against direct rivals can undermine performance while simultaneously fostering sabotage at high rivalry intensity. We discuss the implications of these results for tournament and competition design.