Research Database

This paper derives a variance bounds test for a broad class of linear rational expectations models. According to this test if observed data accords with the model, then a weighted sum of autocovariances of the covariance-stationary components of the endogenous state variables should be nonnegative. The new test reinterprets its forefather - West's [1986] variance bounds test - and extends its applicability by not requiring exogenous state variables in order to be tested. The possibility of the test's application to nonlinear models is also discussed.

This paper argues that versions of Samuelson/Cass-Yaari overlapping-generations consumption-loans models ought to be taken seriously as models of fiat money. The case is made by summarizing and interpreting what these models have to say about fiat money and by arguing that these properties are robust in the sense that they can be expected to hold in any model of fiat money. Two of the properties establish the connection between, on the one hand, the existence of equilibria in which value is attached to a fixed stock of fiat money and, on the other hand, the optimality of such equilibria and the nonoptimality of nonfiat-money equilibria. Other properties describe aspects of the tenuousness of monetary equilibria in such models: The nonuniqueness of such equilibria in the sense that there always exists a nonfiat-money equilibrium and the dependence of the existence of the monetary equilibrium on the physical characteristics of other potential assets and on other institutional features like the tax-transfer scheme in effect. Rather than being defects of these models, it is argued that this tenuousness is helpful in interpreting various monetary systems and, in any case, is unavoidable; it will turn up in any good model of fiat money. Still other properties summarize what these models imply about the connection—or, better, lack of such— between fiat money and private borrowing and lending (financial intermediation) and what they imply about country-specific monies.

We develop a theory of outsourcing in which there is market power in one factor market (labor) and no market power in a second factor market (capital). There are two intermediate goods: one labor-intensive and the other capital-intensive. We show there is always outsourcing in the market allocation when a friction limiting outsourcing is not too big. The key factor underlying the result is that labor demand is more elastic, the greater the labor share. Integrated plants pay higher wages than the specialist producers of labor-intensive intermediates. We derive conditions under which there are multiple equilibria that vary in the degree of outsourcing. Across these equilibria, wages are lower the greater the degree of outsourcing. Wages fall when outsourcing increases in response to a decline in the outsourcing friction.

Under certain assumptions, monopolistic competition with CES preferences is efficient, as first discovered by Dixit and Stiglitz. One assumption, invariably left implicit, is that there are, at any given point in time, no bounds on the number of products that can be discovered. But square wheels do not work, and round wheels keep getting rediscovered. Giving away patents to entrepreneurs who happen to be the first to discover a product generates an inefficiently large amount of variety. The stock of undiscovered products is a commons that can attract too many discovery attempts. Perpetual patents can be efficient, but only when combined with just the right tax on patent-protected monopoly profits. Such a tax is, however, too crude an instrument in an economy with even the least amount of heterogeneity.

The key question asked by standard monetary models used for policy analysis is, How do changes in short-term interest rates affect the economy? All of the standard models imply that such changes in interest rates affect the economy by altering the conditional means of the macroeconomic aggregates and have no effect on the conditional variances of these aggregates. We argue that the data on exchange rates imply nearly the opposite: the observation that exchange rates are approximately random walks implies that fluctuations in interest rates are associated with nearly one-for-one changes in conditional variances and nearly no changes in conditional means. In this sense, standard monetary models capture essentially none of what is going on in the data. We thus argue that almost everything we say about monetary policy using these models is wrong.

Recent developments in the theory of economies with private information permit a re-examination of the issues raised in the "real bills-quantity theory" debate. A model is developed here in which there are banks, in which fiat money is present, and in which agents possess private information. Two regulatory regimes are then considered. In the first, banks are essentially unregulated. In the second, banks face 100 percent reserve requirements. Issues related to existence and optimality of equilibrium are addressed, and problems with existence are given an interpretation in terms of the "stability" of the banking system. Existence (stability) problems which arise under laissez-faire banking can be rectified by a 100 percent reserve requirement. However, unless there is private information regarding access to investment opportunities, there are typically better ways to accomplish this. Finally, it is shown that even in the presence of 100 percent reserve requirements banks are not simply "money warehouses." Bank deposits and money bear different (real) return streams, even under 100 percent reserves.

Wage inequality between education groups in the United States has increased substantially since the early 1980s. The relative number of college-educated workers has also increased dramatically in the postwar period. This paper presents a unified framework where the dynamics of both skill accumulation and wage inequality arise as an equilibrium outcome driven by measured investment-specific technological change. Working through equipment-skill complementarity and endogenous skill accumulation, the model does well in capturing the steady growth in the relative quantity of skilled labor during the postwar period and the substantial rise in wage inequality after the early 1980s. Based on the calibrated model, we examine the quantitative effects of some hypothetical tax-policy reforms on skill accumulation, wage inequality, and welfare.

Starting in the early 1990s, countries in southern Europe experienced low productivity growth alongside declining real interest rates. We use data for manufacturing firms in Spain between 1999 and 2012 to document a significant increase in the dispersion of the return to capital across firms, a stable dispersion of the return to labor, and a significant increase in productivity losses from capital misallocation over time. We develop a model with size-dependent financial frictions that is consistent with important aspects of firms’ behavior in production and balance sheet data. We illustrate how the decline in the real interest rate, often attributed to the euro convergence process, leads to a significant decline in sectoral total factor productivity as capital inflows are misallocated toward firms that have higher net worth but are not necessarily more productive. We show that similar trends in dispersion and productivity losses are observed in Italy and Portugal but not in Germany, France, and Norway.

We study a variation of the standard model of sovereign default, as in Aguiar and Gopinath (2006) or Arellano (2008), and show that this variation is consistent with multiple interest rate equilibria. Some of those equilibria correspond to the ones identified by Calvo (1988), where default is likely because rates are high, and rates are high because default is likely. The model is used to simulate equilibrium movements in sovereign bond spreads that resemble sovereign debt crises. It is also used to discuss lending policies similar to the ones announced by the European Central Bank in 2012.

In this paper we explain why markets in noncontingent debt securities might be a stable form of market organization for intermediation to households. Efficient-contract allocation might be supported by these markets because households' relationships with their intermediaries do not exactly parallel the explicit form of the noncontingent contracts that they explicitly sign with one another. Also we show that the efficient-contract model can be distinguished from alternative models within the time-series framework that has been widely used to study households' consumption patterns.