Research studies have documented a strong link between perennial high rates of beginning teacher attrition and teacher shortages that impact teaching, especially in the major urban areas of the United States. It is widely concluded that one of the pivotal causes of inadequate school academic performance is a teacher shortage and the resulting inability of schools to adequately staff classrooms with qualified teachers. Analysis of national databases on school staffing reveals that many teachers leave teaching or transfer to more affluent schools. The students in the impacted classrooms lose the benefit of being taught by experienced teachers, and schools and districts must commit time and money to recruit and train replacements. Student achievement suffers in schools with high teacher turnover. Trapped in a cycle of teacher hiring and replacement, low-performing disadvantaged schools drain their districts of precious resources that could be better spent to improve teaching quality and student achievement. Improving beginning teachers' work environments, providing more professional development in areas that new teachers find most challenging and increasing support such as induction and mentoring are advocated as having a positive effect on new teacher retention rates. (Contains 2 figures.)