Differential Pay

States should help address chronic shortages and needs.
States should ensure that state-level policies (such as a uniform salary schedule) do not interfere with districts' flexibility in compensating teachers in ways that best meet their individual needs and resources. However, when it comes to addressing chronic shortages, states should do more than simply get out of the way. They should provide direct support for differential pay for effective teaching in shortage subject areas and high-need schools. Attracting effective and qualified teachers to high-need schools or filling vacancies in hard-to-staff subjects are problems that are frequently beyond a district's ability to solve. States that provide direct support for differential pay in these areas are taking an important step in promoting the equitable distribution of quality teachers. Short of providing direct support, states can also use policy levers to indicate to districts that differential pay is not only permissible but necessary.

Differential Pay: Supporting Research
Two recent studies emphasize the need for differential pay. In "Teacher Quality and Teacher Mobility", L. Feng and T. Sass find that high performing teachers tend to transfer to schools with a large proportion of other high performing teachers and students, while low performing teachers cluster in bottom quartile schools. Calder Institute, Working Paper 57, January 2011.  Another study from T. Sass, et al., found that the least effective teachers in high-poverty schools were considerably less effective than the least effective teachers in low-poverty schools http://www.urban.org/UploadedPDF/1001469-calder-working-paper-52.pdf.
C. Clotfelter, E. Glennie, H. Ladd, and J. Vigdor, "Would Higher Salaries Keep Teachers in High-Poverty Schools? Evidence from a Policy Intervention in North Carolina," NBER Working Paper 12285, June 2006.
J. Kowal, B. Hassel, and E. Hassel, "Financial Incentives for Hard-To-Staff Positions: Cross-Sector Lessons for Public Education," Center for American Progress, November 2008.

A study by researchers at Rand found that higher pay lowered attrition, and the effect was stronger in high-needs school districts. Every $1,000 increase was estimated to decrease attrition by more than 6 percent. See S. Kirby, M. Berends, and S. Naftel, "Supply and Demand of Minority Teachers in Texas: Problems and Prospects," Educational Evaluation and Policy Analysis, Volume 21, No. 1, March 20, 1999, pp. 47-66 at: http://epa.sagepub.com/cgi/content/abstract/21/1/47.