This study extends prior research on referee bias and close bias in professional soccer by examining whether Major League Soccer (MLS) referees’ discretion over stoppage time (i.e., extra play beyond regulation) is influenced by end-of-regulation match scores and/or home field advantage. To do...

In a recent study, Beccarini showed that one can eliminate or reduce the bias in OLS regression estimators caused by an omitted polychotomous variable by estimating a regime-switching model. If the missing polychotomous variable assumes K values, then elimination or reduction of the bias...