While there has been substantial research studying the factors that influence teachers' career decisions, there is far less literature on the relationship between teacher effectiveness, mobility, and attrition. In the paper "Teacher Effectiveness, Mobility, and Attrition in Florida: A Descriptive Analysis," Martin West and Matthew Chingos address the topic of teacher effectiveness in Florida. More specifically, they examine how teacher effectiveness is related to teacher mobility and attrition between the 2001-02 and 2005-06 school years, and find that the most effective teachers are not disproportionately leaving their initial job postings, but are slightly more prone to exit the state's teaching workforce. West and Chingos conclude that schools can raise student achievement by implementing targeted policies that keep the highest-performing teachers in the classroom. They stress that future policy should strategically shape attrition rates so as to retain highly effective public school teachers, improve the performance of lower-performing teachers, and encourage chronically low-performing teachers to exit the profession. [This research brief describes work published by the National Center on Performance Incentives in "Teacher Effectiveness, Mobility, and Attrition in Florida: A Descriptive Analysis" by Martin West and Matthew Chingos, Working Paper 2008-12.]