Player Salaries, Player Mobility and the Invariance Principle: Evidence from the National Hockey League

This paper develops a bargaining model of wages and contract length as applied to a professional sports league. Using data based on the recent Collective Bargaining Agreement between players and owners in the National Hockey League, I examine the effect of restrictions on player contracting on both the mobility and salaries of players over the period 2005-2010. Using a variety of estimators both for player mobility and salary determination, I find some evidence that a player’s free agency status effects both mobility and player salaries, but significantly less than might be expected. A key result is that mobility needs to be taken into account when developing models of wage determination in professional sports.