Mehta, JalCohen, David2017-06-212017Mehta, Jal, and David Cohen. 2017. Why Reform Sometimes Succeeds: Understanding the Conditions That Produce Reforms That Last. American Educational Research Journal. Forthcoming. doi:10.3102/0002831217700078.00028312http://nrs.harvard.edu/urn-3:HUL.InstRepos:33064054Counter to narratives of persistently failed school reform, we argue that reforms sometimes succeed, and seek to understand why. Drawing on examples from the founding of public schools to the present, we find that successful system-wide reforms addressed problems that teachers thought they had, by being consistent with prevailing norms and values, by mobilizing a significant public constituency, and building the needed educational infrastructure. We distinguish between system-wide and niche reforms, suggesting that some--particularly those seeking ambitious instruction—failed system-wide but succeeded by creating protected educational niches. We conclude with a discussion of the implications for the Common Core.en-USnicheambitious instructionhistory of educationpolitics of educationschool reformJournal Article2017-06-0120172017-06-2110.3102/0002831217700078