It is shown that the Medoff economic hypothesis of stacking, based on free choice induced by income differentials and training cost differentials, cannot generate unambiguous predictions. Latin American players in baseball are given as a counterexample. Means to ascertain the training costs relative to each position are suggested, as well as means to predict the evolution of positional segregation in baseball through time, using the uncertainty thesis of discrimination put forth by Blalock and previously applied to ice hockey.
Marc Lavoie is with the Department of Economics at the University of Ottawa, 550 Cumberland St., Ottawa, Ont. KIN 6N5.