Empirical research on the permanent income hypothesis (PIH) has found that consumption growth is excessively sensitive to predictable changes in income. This finding is interpreted as strong evidence against the PIH. We propose an explanation for apparent excess sensitivity that is based on a...

This paper uses propensity score methods to address the question: how well can an observational study estimate the treatment impact of a program? Using data from Lalonde's (1986) influential evaluation of non-experimental methods, we demonstrate that propensity score methods succeed in...

The recent experimental evaluation of the U.S. Job Training Partnership Act (JTPA) program found negative effects of training on the earnings of disadvantaged male youth and no effect on the earnings of disadvantaged female youth. These findings provided justification for Congress to cut the...

The literature on class size yields a number of findings. First, class size effects are difficult to find except when using data where class size variations are truly exogenous. Second, Catholic schools have large classes and better performance. Third, to the extent that class size matters, it...

A growing number of roads are currently financed by the private sector via Build-Operate-and -Transfer (BOT) schemes. When the franchised road has no close substitute, the government must regulate tolls. Yet when there are many ways of getting from one point to another, regulation may be avoided...

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...

We examine two factors that might explain the extent of air traffic delays in the United States: network benefits due to hubbing and congestion externalities. Airline hubs enable passengers to cross-connect to many destinations, thus creating network benefits that increase in the number of...

In countries, such as Singapore, that have implemented vehicle congestion policies, recent years have seen a shift towards motor vehicle taxes based on car use. Ownership taxes reduce the number of cars on the road, leaving the price per trip largely unaffected. Use taxes such as fuel taxes and...

There are constraints on pricing congestible facilities. First, if heterogeneous users are observationally indistinguishable, then congestion charges must be anonymous. Second, the time variation of congestion charges may be constrained. Do these constraints undermine the feasibility of marginal...

This paper establishes the existence of multiple equilibria in infinite-horizon open- economy models in which the value of tradable and nontradable endowments serves as collateral. In this environment, the economy displays self-fulfilling financial crises in which pessimistic views about the...