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...