While substantial school choice research focuses on student achievement outcomes, little has explored the mechanisms involved in producing such outcomes. We present a comparative analysis of private and public school principals using data from the School and Staffing Survey (SASS) 2011-2012. We add to the literature by examining the differences in private and public school principals' abilities to influence important decisions at their schools from a nationally representative sample of 9,230 school principals. Results indicate that private school leadership exhibits more autonomy in influencing school level policies, perhaps explaining private school advantages.