The effects of changing teams on the performance of major league baseball players

Using archival data on the performance of major league baseball players from 1970 to 1989, this paper examines the effects of changing teams on individual performance. We replicate and expand on earlier studies by using multiple and novel measures of performance, by extending the analysis to the performance of both hitters and pitchers, and by examining for the first time how free agents respond to moving between teams. The findings show that both hitters and pitchers involved in mid-season trades showed significant post-trade improvements following sub-par performances prior to being traded. Pitchers and hitters traded between seasons also enjoyed better years with their new teams although performance improvements for pitchers did not last beyond the season following a trade. Free agents, whether hitters or pitchers, showed no improvements after signing contracts with new teams and a deterioration in performance in their second year with a new team.
The present study examines the effects of changing teams on the performance of major league baseball players. As established in previous research on professional hockey players (White, McTeer & Vagi, [...]