Models of voting, including the canonical rational voter model, predict that voters are more likely to turn out when they anticipate a closer election. Yet, evidence of a causal effect of anticipated election closeness on voter turnout is limited. We exploit naturally occurring variation in the...

We study how the politicization of policies designed to correct market failures can undermine their effectiveness. The Patient Protection and Affordable Care Act (ACA) was among the most politically divisive expansions of the US government. We examine whether partisanship distorted enrollment...

Citizens have long taken to the streets to demand change, expressing political views that may otherwise be suppressed. Protests have produced change at local, national, and international scales, including spectacular moments of political and social transformation. We document five new empirical...

We study the causal effect of school curricula on students' stated beliefs and attitudes. We exploit a major textbook reform in China that was rolled out between 2004 and 2010 with the explicit intention of shaping youths' ideology. To measure its effect, we present evidence from a novel survey...

We present new data documenting medieval Europe's "Commercial Revolution'' using information on the establishment of markets in Germany. We use these data to test whether medieval universities played a causal role in expanding economic activity, examining the foundation of Germany's first...

The analysis of historical natural experiments has profoundly impacted economics research across fields. We trace the development and increasing application of the methodology, both from the perspective of economic historians and from the perspective of economists in other subdisciplines. We...

Using novel microdata, we document an unintended, first-order consequence of the Protestant Reformation: a massive reallocation of resources from religious to secular purposes. To understand this process, we propose a conceptual framework in which the introduction of religious competition shifts...

The decision to protest is strategic: an individual's participation is a function of her beliefs about others' turnout. Models of protest often assume strategic complementarity; however, the challenge of collective action suggests strategic substitutability. We conduct the first field experiment...

Identifying the role of intrinsic, ideological motivation in political behavior is confounded by agents' consequential aims and social concerns. We present results from two experiments that implement a methodology isolating Pakistani men's intrinsic motives for expressing anti-American ideology,...

Using a high-stakes field experiment conducted with a financial brokerage, we implement a novel design to separately identify two channels of social influence in financial decisions, both widely studied theoretically. When someone purchases an asset, his peers may also want to purchase it, both...