The establishment of the free agency system in the 1970s resulted in large salary increases among professional baseball players. Historical data show that players have tended to perform better at early stages of their careers since free agency was introduced. Under the current salary bargaining...

The establishment of the free agency system in the 1970s resulted in large salary increases among professional baseball players. Historical data show that players have tended to perform better at early stages of their careers since free agency was introduced. Under the current salary bargaining...

A detailed longitudinal dataset is assembled containing annual performance and biographical data for every player over the entire history of professional major league baseball. The data are then aggregated to the team level for the period 1920-2009 in order to test whether teams built on a more...