This study focuses on 256 Major League Baseball free agent hitters playing under the 2006–2011 collective bargaining agreement to determine whether players engage in opportunistic behavior in their contract year, i.e., the last year of their current guaranteed contracts. Past studies of professional baseball yield conflicting results depending on the econometric technique applied and choice of performance measure. When testing whether players’ offensive performances increase during their contract year, the omitted variable bias associated with OLS and pooled OLS estimation leads to contrary results compared to fixed effects modeling. Fixed effects regression results suggest players increase their offensive performance subject to controlling for the intention to retire.
O'Neill, Heather M., "Do Major League Baseball Hitters Engage in Opportunistic Behavior?" (2013). Business and Economics Faculty Publications. 6.