10.2190/9XM2-19G5-815A-57TC 9XM219G5815A57TC 0 THE EFFECTS OF TEACHER UNIONS ON THE PROBABILITY OF DROPPING OUT OF HIGH SCHOOL 20020509 20020509 20020509 20020509 http://baywood.metapress.com/link.asp?target=contribution&id=9XM219G5815A57TC 3 HARRIS L. ZWERLING AND TERRY THOMASON The results reported in this article generally show important differences exist, affecting the probability of dropping out of high school for male and female students. In particular, the union status of the high school is more likely to affect the dropout probability of male students. We speculate this effect is due to the standardization of instruction induced by teacher unions. At a minimum, these results suggest teacher unions do not increase the probability of dropout and may reduce it, thus possible improving one dimension of the performance of America's public education system. These results contrast with the description of the impact of teacher unions offered by many of those who are calling for radical reform of that system.