Work for this study was funded by the Joyce Foundation and IES Award R305B090016. Any errors or oversights are our own. We would like to thank Andres Cantero Jr. for his data collection efforts and Abstract: The assumption that choice-driven competition between schools will improve school quality rests upon several assumptions that remain largely unexamined. One is that school choice increases the competitive pressure experienced by school leaders. A second is that schools will seek to become more effective in response to competitive pressure. In this paper, we use responses from a survey of Milwaukee public school principals to examine these assumptions. Our results suggest that there is a substantial amount of variation in how principals experience competitive pressure. Somewhat surprisingly, the extent to which principals perceive competition for students is not related to geographic factors such as the number of nearby schools serving overlapping grades, the average distance to another school, or the distance to the closest school. However, perceptions of competition are related to student achievement as well as to transfer rates out of a school. This study provides evidence that while some schools respond to competition by trying to improve through curricular or instructional changes, a more common approach is to use outreach or advertisement which is may not improve the quality of schooling.