We combine data on trade, production, and input use to compute the value added content of trade for forty-two countries from 1970 to 2009. For the world, the ratio of value added to gross trade falls by ten to fifteen percentage points, with two-thirds of this decline in the last two decades....

We develop a property-rights model of the firm in which production entails a continuum of uniquely sequenced stages. In each stage, a final-good producer contracts with a distinct supplier for the procurement of a customized stage-specific component. Our model yields a sharp characterization for...

This paper makes two methodological contributions. First, it proposes a framework to decompose total production activities at the country, sector, or country-sector level, to different types, depending on whether they are for pure domestic demand, traditional international trade, simple GVC...

We combine data on trade, production, and input use to document changes in the value added content of trade between 1970 and 2009. The ratio of value-added to gross exports fell by roughly 10 percentage points worldwide. The ratio declined 20 percentage points in manufacturing, but rose in...

We present results about the effects of observing others' choices, called observational learning, on individuals' behavior and subjective well-being in the context of restaurant dining from a randomized natural field experiment. Our experimental design aims to distinguish observational learning...

We conduct a large scale RCT to investigate peer effects in computer assisted learning (CAL). Identification of peer effects relies on three levels of randomization. It is already known that CAL improves math test scores in Chinese rural schools. We find that paired treatment improves the...

This paper characterizes heterogeneity of the beliefs of American households about future stock market returns, provides an explanation for that heterogeneity and establishes its relationship to stock holding behavior. We find substantial belief heterogeneity that is puzzling since households...

I develop a model in which a child's acquisition of a given form of human capital incentivizes adults in his household to either learn from him (if children act as teachers then adults' cost of learning the skill falls) or lean on him (if children's human capital substitutes for that of adults...

Recent medical research shows that health is highly influential for learning and the ability to think laterally; however, past economic studies have failed to empirically examine the influence of health on learning, schooling, and ideas production; the main drivers of growth in endogenous growth...

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...