We mailed letters to non-existent business addresses in 159 countries (10 per country), and measured whether they come back to the return address in the US and how long it takes. About 60% of the letters were returned, taking over 6 months, on average. The results provide new objective...

There is growing interest in using messaging to drive prosocial behaviors, which contribute to investment in public goods. The authors worked with a leading nongovernmental organization in Peru to randomize nine different prorecycling messages that were crafted on the basis of best practices,...

This paper investigates the potential of information technology to improve public service delivery and empower citizens. The investigation uses two randomized natural experiments in the renewal of national identification cards by the Bolivian Police. The first experiment arises from the random...

Evidence from historical and epidemiological literatures show that epidemics tend to spread in the population according to a logistic pattern. We conjecture that the impact of new technologies on output follows a pattern of spread not unlike that of typical epidemics. After reaching a critical...

This paper extends Grossman and Helpman’s seminal work (1991), and presents an endogenous growth model where innovations created in a high-tech sector may be assimilated or adapted by a low-tech sector. Applying a simple Heckscher-Ohlin framework, the effects of technological diffusion are...

In the last dozen years, economists have produced a considerable body of research suggesting that the historical origin of a country’s laws is highly correlated with a broad range of its legal rules and regulations, as well as with economic outcomes. Much of this research has dealt with rules...

We investigate the determinants of regional development using a newly constructed database of 1569 sub-national regions from 110 countries covering 74 percent of the world's surface and 96 percent of its GDP. We combine the cross-regional analysis of geographic, institutional, cultural, and...