Research Database

How much discretion should the monetary authority have in setting its policy? This question is analyzed in an economy with an agreed-upon social welfare function that depends on the randomly fluctuating state of the economy. The monetary authority has private information about that state. In the model, well-designed rules trade off society’s desire to give the monetary authority discretion to react to its private information against society’s need to guard against the time inconsistency problem arising from the temptation to stimulate the economy with unexpected inflation. Although this dynamic mechanism design problem seems complex, society can implement the optimal policy simply by legislating an inflation cap that specifies the highest allowable inflation rate. The more severe the time inconsistency problem and the less important is private information, the smaller is the optimal degree of discretion. As either the time inconsistency problem becomes sufficiently severe or private information becomes sufficiently unimportant, the optimal degree of discretion is none.

When credit markets to finance investment in human capital are missing, the competitive equilibrium allocation is inefficient. When generations overlap, this failure can be mitigated by properly designed social arrangements. We show that public financing of education and public pensions can be designed to implement an intergenerational transfer scheme supporting the complete market allocation. Neither the public financing of education nor the pension scheme we consider resemble standard ones. In our mechanism, via the public education system, the young borrow from the middle aged to invest in human capital. They pay back the debt via a social security tax, the proceedings of which finance pension payments. When the complete market allocation is achieved, the rate of return implicit in this borrowing-lending scheme should equal the market rate of return.

Many kinds of economic behavior involve discrete and occasional individual choices. Despite this, econometric partial adjustment models perform relatively well at the aggregate level. Analyzing the classic employment adjustment problem, we show how such microeconomic adjustment is well described by a new form of partial adjustment model that aggregates the actions of heterogeneous producers.

We develop a model where individual establishments infrequently alter the sizes of their workforces because such adjustments involve fixed costs. In the market equilibrium, employment responses to aggregate disturbances include changes both in target employments selected by individual establishments and in the measure of establishments actively undertaking adjustment. Yet the model retains a partial adjustment flavor in its aggregate responses. Moreover, in contrast to existing discrete adjustment models, our generalized partial adjustment model is sufficiently tractable to allow general equilibrium analysis, and it naturally extends to accommodate persistent differences in productivity across establishments in general equilibrium.

We solve equilibrium models of lumpy investment wherein establishments face persistent shocks to common and plant-specific productivity. Nonconvex adjustment costs lead plants to pursue generalized (S, s) rules with respect to capital; thus, their investments are lumpy. In partial equilibrium, this yields substantial skewness and kurtosis in aggregate investment, though, with differences in plant-level productivity, these nonlinearities are far less pronounced. Moreover, nonconvex costs, like quadratic adjustment costs, increase the persistence of aggregate investment, yielding a better match with the data. In general equilibrium, aggregate nonlinearities disappear, and investment rates are very persistent, regardless of adjustment costs. While the aggregate implications of lumpy investment change substantially in equilibrium, the inclusion of fixed costs or idiosyncratic shocks makes the average distribution of plant investment rates largely invariant to market-clearing movements in real wages and interest rates. Nonetheless, we find that understanding the dynamics of plant-level investment requires general equilibrium analysis.

This paper studies the relation between the United States’ bilateral real exchange rate and the associated bilateral relative price of nontraded goods for five of its most important trade relationships. Traditional theory attributes fluctuations in real exchange rates to changes in the relative price of nontraded goods. We find that this relation depends crucially on the choice of price series used to measure relative prices and on the choice of trade partner. The relation is stronger when we measure relative prices using producer prices rather than consumer prices. The relation is stronger the more important is the trade relationship between the United States and a trade partner. Even in cases where there is a strong relation between the real exchange rate and the relative price of nontraded goods, however, a large fraction of real exchange rate fluctuations is due to deviations from the law of one price for traded goods.

We study dynamic optimal taxation in a class of economies with private information. Constrained optimal allocations in these environments are complicated and history-dependent. Yet, we show that they can be implemented as competitive equilibria in market economies supplemented with simple tax systems. The market structure in these economies is similar to that in Bewley (1986): agents supply labor and trade risk-free claims to future consumption, subject to a budget constraint and a debt limit. Optimal taxes are conditioned only on two observable characteristics—an agent’s accumulated stock of claims, or wealth, and her current labour income—and they are not additively separable in these variables. The marginal wealth tax is decreasing in labour income and its expected value is generally positive. The marginal labour income tax is decreasing in wealth.

In this paper, we generalize the notion of Pareto-efficiency to make it applicable to environments with endogenous populations. Two efficiency concepts are proposed, P-efficiency and A-efficiency. The two concepts differ in how they treat people who are not born. We show how these concepts relate to the notion of Pareto-efficiency when fertility is exogenous. We then prove versions of the first welfare theorem assuming that decision making is efficient within the dynasty. Finally, we give two sets of sufficient conditions for noncooperative equilibria of family decision problems to be efficient. These include the Barro and Becker model as a special case.

This paper describes an analytically tractable model of balanced growth that allows for extensive heterogeneity in the technologies used by firms. Firms enter with fixed characteristics that determine their initial technologies and the levels of fixed costs required to stay in business. Each firm produces a different good, and firms are subject to productivity and demand shocks that are independent across firms and over time. Firms exit when revenues are too low relative to fixed costs. Conditional on fixed firm characteristics, the stationary distribution of firm size satisfies a power law for all sizes above the size at which new firms enter. The tail of the size distribution decays very slowly if the growth rate of the initial productivity of potential entrants is not too far above the growth rate of productivity inside incumbent firms. In one interpretation, this difference in growth rates can be related to learning-by-doing inside firms and spillovers of the information generated as a result. As documented in a companion paper, heterogeneity in fixed firm characteristics together with idiosyncratic firm productivity growth can generate entry, exit, and growth rates, conditional on age and size, in line with what is observed in the data.

This article describes changes in the number of average weekly hours of market work per person in the United States since World War II. Overall, this number has been roughly constant; for various groups, however, it has shifted dramatically—from males to females, from older people to younger people, and from single- to married-person households. The article provides a detailed look at how the lifetime pattern of work hours has changed since 1950 for different demographic groups. This article also documents several factors that lead to the reallocation of hours worked across groups: increases in relative wages of females to males; technological innovations that shift female labor from the home to the market; increases in Social Security benefits to retired workers; and changes in family structure. The data presented are based on those collected by the U.S. Bureau of the Census during the 1950–2000 decennial censuses.

Entrepreneurship is a key determinant of investment, saving, wealth holdings, and wealth inequality. We study the aggregate and the distributional effects of several tax reforms in a model that recognizes the key role played by the entrepreneurs, and that matches very well the extreme degree of wealth inequality observed in the U.S. data. We find that the effects of tax reforms on output and capital formation can be particularly large when they affect the majority of small and medium-size businesses, which face the most severe financial constraints, rather than a small number of big businesses. We show that the consequences of changes in the estate tax depend heavily on the size of its exemption level. The current effective estate tax system seems to insulate most of the businesses from the negative effects of estate taxation thus minimizing the aggregate costs of redistribution. Abolishing the current estate tax would generate a modest increase in wealth inequality and slightly reduce aggregate output. Decreasing progressivity of the income tax can generate large increases in output, as this stimulates entrepreneurial savings and capital formation, but at the cost of large increases in wealth concentration.