 He is also known for his work to improve the accurate reporting of high school graduation rates, address financial incentives in special education, and the use of standardized tests to curb social promotion.His research was cited four times in the Supreme court opinions in the landmark Zelman v. Simmons-Harris case on school vouchers.His research has appeared in academic journals, such as "Education Finance and Policy", "Economics of Education Review", and "Educational Evaluation and Policy Analysis", as well as in major newspapers, such as the "Wall Street Journal", "New York Times", and the "Washington Post".