A protege of 2012 Nobel Prize winner Alvin E. Roth, Pathak is best known for his work in market design. He is a leader in the recent push to apply engineering methods to microeconomics. As a graduate student, Pathak worked with Roth to design the algorithm underlying the system used to match New York City public school students to high schools as incoming freshman. Around the same time, he worked together with Atila Abdulkadiroglu, Roth, and Tayfun Sönmez to design a new student assignment system for Boston Public Schools, which was adopted in 2005. The team of economists identified parents in Boston who developed heuristics on how to play this real-world game so that their children would not be unassigned, leaving those unaware of these features disadvantaged. Boston held citywide discussions and hearings on the school selection system and finally in 2005 narrowed the choice to one of two mechanisms: the top trading cycles mechanism for schools and the student-optimal stable mechanism based on the stable marriage problem. Eventually, Boston adopted the student-optimal stable mechanism. The policy change was the first time an incentive compatiblestrategyproof mechanism, based on an abstract concept from mechanism design, played a role in a public policy discussion. This work was recognized in the 2012 Nobel Memorial Prize in Economic Sciences awarded to Alvin E. Roth and Lloyd Shapley ``for the theory of stable allocations and the practice of market design.'' Since then, a number of other districts have abandoned Boston's old mechanism. In 2007, through an act of Parliament, British authorities outlawed the use of First Preference First arrangements, which made Boston's old method of school assignment illegal throughout 150 English districts. Pathak continues to be involved with the Boston school choice plan. In 2012, Boston Mayor Thomas Menino asked for Pathak's help by appointing him the Technical Advisor to the Boston School Choice Plan. The city embarked on a discussion of several alternative zone plans, including the complete elimination of school choice, and Mayor Menino commissioned a report evaluating the alternative proposals. This frustrated some groups because it delayed citywide discussions about Boston's choice plan. After the report was released, some parent groups were unhappy even though it made no recommendations. In 2013, the school committee adopted a proposal developed by one of Pathak's graduate student. The proposal was controversial and seen as complicated. Nonetheless, members of the Boston school committee voted for it because it was the best compromise between competing objectives. Pathak helped to design the OneApp common enrollment system used in the Recovery School District in New Orleans in 2011, involving a collaboration of assignment processes between charter schools and traditional public schools.
Education reform
Pathak is also a leading scholar in education reform. He is most well known for numerous studies of charter schools which use randomness in assignment lotteries to deal with differences between charter and traditional students. One study compares Boston's charter, pilot and traditional schools, and finds Boston's charter schools to be unusually effective. A report by the Boston Teacher's Union criticized the report, claiming that they could not generalize the methodology to less-popular schools without waiting lists. He also conducted the first such study of a KIPP charter school. Work with Joshua Angrist finds that charter schools outside of urban areas are not particularly effective. Another study considers the effects of Boston's charter schools on college enrollment and persistence. A more controversial study examines the effects of Boston and New York's exam schools finding that the high achievement of these students is not due to the school, but to the school's admissions process. Even though they continue to remain popular among parents, the Washington Post's Jay Mathews wondered if exam schools are even needed based on the study.
Other
Pathak has also studied the effect of home foreclosures on home prices in their surrounding neighborhood. This work has been cited in congressional testimony and featured in several outlets including PBS and NPR.