Most central banks perceive a trade-off between stabilizing inflation and stabilizing the gap between output and desired output. However, the standard new Keynesian framework implies no such trade-off. In that framework, stabilizing inflation is equivalent to stabilizing the welfare-relevant...

This essay describes the current debate on reforming Social Security in the US, along with a brief description of how the program works. Along the way it comments on the quality of some proposed reform proposals as well as their political standing. Where issues are similar, some inferences are...

This paper argues that a risk-averse worker's after-tax reservation wage encodes all the relevant information about her welfare. This insight leads to a novel test for the optimality of unemployment insurance based on the responsiveness of reservation wages to unemployment benefits. Some...

We construct a model of simultaneous change and persistence in institutions. The model consists of landowning elites and workers, and the key economic decision concerns the form of economic institutions regulating the transaction of labor (e.g., competitive markets versus labor repression). The...

Why do inefficient - non-growth enhancing - institutions emerge and persist? This paper develops a simple framework to provide some answers to this question. Political institutions determine the allocation of political power, and economic institutions determine the framework for policy-making...

We study the efficiency of oligopoly equilibria in a model where firms compete over capacities and prices. The motivating example is a communication network where service providers invest in capacities and then compete in prices. Our model economy corresponds to a two-stage game. First, firms...

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...

Most large-scale communication networks, such as the Internet, consist of interconnected administrative domains. While source (or selfish) routing, where transmission follows the least cost path for each source, is reasonable across domains, service providers typically engage in traffic...

Microeconomic lumpiness matters for macroeconomics. According to our DSGE model, it explains roughly 60% of the smoothing in the investment response to aggregate shocks. The remaining 40% is explained by general equilibrium forces. The central role played by micro frictions for aggregate...

We study the efficiency of oligopoly equilibria in congested markets. The motivating examples are the allocation of network flows in a communication network or of traffic in a transportation network. We show that increasing competition among oligopolists can reduce efficiency, measured as the...