Users of the social networking service Facebook have the possibility to post status updates for their friends to read. In turn, friends may react to these short messages by writing comments or by pressing a Like button to show their appreciation. Making use of five Swedish accounts, we set up a...

This paper analyzes peer effects among university scientists. Specifically, it investigates whether the number of peers and their average quality affects the productivity of researchers in physics, chemistry, and mathematics. The usual endogeneity problems related to estimating peer effects are...

Using cultural transmission, we develop a model that gives some microfoundation to the impact of residential neighborhood on children's educational attainment and then test it using the UK National Child Development Study. We find that, for high-educated parents, the better the quality of the...

This paper presents a simple model of strategic network formation with local complementarities in effort levels and positive local externalities for a general class of payoff functions. Results are obtained for one-sided and two-sided link creation. In both cases (pairwise) Nash equilibrium...

Many firms encourage employees to own company stock through share plans that subsidizethe price at favorable rates, but even so many employees do not buy shares. Using a newsurvey of employees in a multinational with a share ownership plan, we find considerablevariation in joining among...

We conduct a controlled lab-field experiment to directly test the short-run spillover effects of one-off financial incentives in health. We consider how incentives affect effort in a physical activity task – and then how they spillover to subsequent eating behaviour. Compared to a control...

No behavior sits in a vacuum, and one behavior can greatly affect what happens next. We propose a conceptual frame within which a broad range of behavioral spillovers can be accounted for when applying behavioral science to policy challenges. We consider behaviors which take place sequentially...

We test whether people’s tendency to stick with the default option can help save resources. In a natural field experiment we switch printers’ default settings, from simplex to duplex printing, at a large Swedish university. The results confirm that roughly one third of all printing is...

Nonparametric regression is developed for data with both a temporal and a cross-sectional dimension. The model includes additive, unknown, individual-specific components and allows also for cross-sectional and temporal dependence and conditional heteroscedasticity. A simple nonparametric...

The introduction of antibiotics as a medical treatment after World War II helped to dramatically increase life expectancy in the industrialized world. However, over-prescription of antibiotics during the last few decades has led to a sharp increase in multi-resistant bacteria, disarming once...