The growing call to close the achievement gap and to link teacher pay with student achievement is often blind to the reality of the many powerful influences on the lives of children, including how they perform in school.
See this important study: Basch, C.E. (2010). Healthier Students Are Better Learners: A Missing Link in Efforts to Close the Achievement Gap. Equity Matters: Research Review No. 6. New York: The Campaign for Educational Equity.