A theory of leadership is proposed and tested. Leaders are characterized as those who have the ability to choose the right direction more frequently than their peers. The theory implies that leaders tend to be more able, place themselves in visible decision making situations more frequently, and...

Numerous evaluations show that conditional cash transfer programs change households' investments in their young children, but there are many open questions about how such changes can be sustained after transfers end. This paper analyzes the role of social interactions with local female leaders...

The US Civil War provides researchers a unique opportunity to identify wartime leaders and thus to test theories of leadership. By observing both leaders and followers during the war and forty years after it, I establish that the most able became wartime leaders, that leading by example from the...

We model social media as collections of users producing and consuming content. Users value consuming content, but doing so uses up their scarce attention, and hence they prefer content produced by more able users. Users also value receiving attention, creating the incentive to attract an...

Using newly validated data on geographic migration networks, we study how labor demand shocks in the United States propagate across the border with Mexico. We show that the large exogenous decline in US employment brought about by the Great Recession affected demographic and economic outcomes in...

We analyze the diffusion of rival information in a social network. In our model, rational agents can share information sequentially, unconstrained by an exogenous protocol or timing. We show how to compute the set of eventually informed agents for any network, and show that it is essentially...

We present a model of online content sharing where agents sequentially observe an article and must decide whether to share it with others. The article may contain misinformation, but at a cost, agents can fact-check it to determine whether its content is entirely accurate. While agents derive...

An information cascade is a situation in which an agent who observes others chooses the same action irrespective of the value of the agent's private information signal. Theoretical models have found that cascades result in poor information aggregation, inaccurate decisions, and fragility of mass...

This paper uses the concept of the triad census first introduced by Holland and Leinhardt, and describes several distributions on directed graphs. Methods are presented for calculating the mean and the covariance matrix of the triad census for the uniform distribution that conditions on the...

We introduce the concept of a triad census of a digraph arid show how it can be used to enumerate various types of subgraph configurations. We give the basic probabilities needed for computing means and variances for a triad census under the U-MAN distribution for digraphs. These concepts are...