We study the effects of various types of education and training on the ability of teachers to promote student achievement. Previous studies on the subject have been hampered by inadequate measures of teacher training and difficulties addressing the non-random selection of teachers to students and of teachers to training. We address all of these limitations by estimating models with student, teacher, and school fixed effects using an extensive database from the state of Florida. Our results suggest that teacher training generally has little influence on productivity. One exception is that content-focused teacher professional development is positively associated with productivity in middle and high school math. In addition, more experienced teachers appear more effective in teaching elementary and middle school reading. There is no evidence that either preservice (undergraduate) training or the scholastic aptitude of teachers influences their ability to increase student achievement. These results call into question previous findings based on models that do not adequately control for the various forms of selection bias.