Research Database

A definition of a transactions medium is proposed. This is that a transactions medium permits the attainment of otherwise unattainable resource allocations. It is shown that by this definition money can be a transactions medium in a pure exchange, overlapping generations economy. It is also shown that money is a transaction medium only if there are informational asymmetries of a particular type. Finally, it is shown that the set of economies for which money is a transactions medium is not isolated, in a well-defined sense.

The normal linear model, with sign or other linear inequality constraints on its coefficients, arises very commonly in many scientific applications. Given inequality constraints Bayesian inference is much simpler than classical inference, but standard Bayesian computational methods become impractical when the posterior probability of the inequality constraints (under a diffuse prior) is small. This paper shows how the Gibbs sampling algorithm can provide an alternative, attractive approach to inference subject to linear inequality constraints in this situation, and how the GHK probability simulator may be used to assess the posterior probability of the constraints.

The classic explanation for the persistence and volatility of real exchange rates is that they are the result of nominal shocks in an economy with sticky goods prices. A key implication of this explanation is that if goods have differing degrees of price stickiness then relatively more sticky goods tend to have relatively more persistent and volatile good-level real exchange rates. Using panel data, we find only modest support for these key implications. The predictions of the theory for persistence have some modest support: in the data, the stickier is the price of a good the more persistent is its real exchange rate, but the theory predicts much more variation in persistence than is in the data. The predictions of the theory for volatility fare less well: in the data, the stickier is the price of a good the smaller is its conditional variance while in the theory the opposite holds. We show that allowing for pricing complementarities leads to a modest improvement in the theory’s predictions for persistence but little improvement in the theory’s predictions for conditional variances.

This paper uses an estimated structural model to argue that the option to move in and out of the parental home is an important insurance channel against labor market risk for youths who do not attend college. Using data from the NLSY97, I construct a new monthly panel of parent-youth coresidence outcomes and use it to document an empirical relationship between these movements and individual labor market events. The data is then used to estimate the parameters of a dynamic game between youths and their altruistic parents, featuring coresidence, labor supply and savings decisions. Parents can provide both monetary support through explicit financial transfers, and non-monetary support in the form of shared residence. To account for the data, two types of exogenous shocks are needed. Preference shocks are found to explain most of the cross-section of living arrangements, while labor market shocks account for individual movements in and out of the parental home. I use the model to show that coresidence is a valuable form of insurance, particularly for youths from poorer families. The option to live at home also helps to explain features of aggregate data for low-skilled young workers: their low savings rates and their relatively small consumption responses to labor market shocks. An important implication is that movements in and out of home can reduce the consumption smoothing benefits of social insurance programs.

Previous literature has shown that the study and characterization of constrained efficient allocations in economies with limited enforcement is useful to understand the limited risk sharing observed in many contexts, in particular between sovereign countries. In this paper we show that these constrained efficient allocations arise as equilibria in an economy in which private agents behave competitively, taking as given a set of taxes. We then show that these taxes, which end up limiting risk sharing, arise as an equilibrium of a dynamic game between governments. Our decentralization is different from the existing ones proposed in the literature. We find it intuitively appealing and we think it goes farther than the existing literature in endogenizing the primitive forces that lead to a lack of risk sharing in equilibrium.

We construct a vintage capital model of economic growth in which the decision to replace old technologies with new ones is modeled explicitly. Depreciation in this environment is an economic, not a physical concept. We describe the balanced growth paths and the transitional dynamics of this economy. We illustrate the importance of vintage capital by analyzing the response of the economy to fiscal policies designed to stimulate investment in new technologies.