A principal provides budgets to agents (e.g., divisions of a firm or the principal's children) whose expenditures provide her benefits, either materially or because of altruism. Only agents know their potential to generate benefits. We prove that if the more "productive" agents are also more...

We study the predictive power of approximately 2.5 million stock picks submitted by individual users to the “CAPS†website run by the Motley Fool company (www.caps.fool.com). These picks prove to be surprisingly informative about future stock prices. Indeed, a strategy of shorting...

Increasing political and economic interconnectedness draws much philosophical attention to the question of the conditions under which such stringent claims arise. Do claims of justice arise only among those who share membership in a state? Alternatively, do they arise among all those who are...

This study assesses the factors influencing the movement of people across health plans. We distinguish three types of cost-related transitions: adverse selection, the movement of the less healthy to more generous plans; adverse retention, the tendency for people to stay where they are when they...

Behavioral decision research has profoundly changed our understanding of decision-making. Recent research has begun to explore how behavioral insights can influence behavior in the world, at scale. This work often involves field experiments studying outcomes over short time windows. We study a...

A number of development assistance programs promote community interaction as a means of building social capital. Yet, despite strong theoretical underpinnings, the role of repeat interactions in sustaining cooperation has proven difficult to identify empirically. We provide the first...

We study the structure of international aid coordination by creating and analyzing a tripartite network of donor organizations, recipient countries and development issues using web-based information. We develop a measure of coordination and find that it is moderate, achieving about 60% of its...

Nuclear terrorism is a real and urgent threat. Given the potentially catastrophic consequences, even a small probability of terrorists getting and detonating a nuclear bomb is enough to justify urgent action to reduce the risk. Al-Qaeda and North Caucasus terrorist groups have both made...

Why are some civic associations more effective than others? The authors introduce a multidimensional framework for analyzing the effectiveness of civic associations in terms of public recognition, member engagement, and leader development. Using original surveys of local Sierra Club...

We document the loan provisions in 401(k) savings plans and how participants use 401(k) loans. Although only about 22% of savings plan participants who are allowed to borrow from their 401(k) have such a loan at any given point in time, almost half had used a 401(k) loan over a longer,...