We build a model of firm-level innovation, productivity growth and reallocation featuring endogenous entry and exit. A key feature is the selection between high- and low-type firms, which differ in terms of their innovative capacity. We estimate the parameters of the model using detailed US...

Educational resources distributed via the Internet are rapidly proliferating. One prominent concern associated with these potentially transformative developments is that, as many of the leading technologies of the last several decades have been, these new sweeping technological changes will be...

We develop a theoretical model of security investments in a network of interconnected agents. Network connections introduce the possibility of cascading failures, due to an exogenous or endogenous attack, depending on the profile of security investments by the agents. The general presumption in...

We show that, in a model without commitment to future policies, geoengineering breakthroughs can have adverse environmental and welfare effects because they change the (equilibrium) carbon taxes. In our model, energy producers emit carbon, which creates a negative environmental externality, and...

Is inequality harmful for economic growth? Is the underdevelopment of Latin America related to its unequal distribution of wealth? A recently emerging consensus claims not only that economic inequality has detrimental effects on economic growth in general, but also that differences in economic...

Inefficiencies in the bureaucratic organization of the state are often viewed as important factors in retarding economic development. Why certain societies choose or end up with such inefficient organizations has received very little attention, however. In this paper, we present a simple theory...

We document substantial within-country (cross-municipality) differences in incomes for a large number of countries in the Americas. A significant fraction of the within-country differences cannot be explained by observed human capital. We conjecture that the sources of within-country and...