Research Database

A framework is developed with what we call technology capital. A country is a measure of locations. Absent policy constraints, a firm owning a unit of technology capital can produce the composite output good using the unit of technology capital at as many locations as it chooses. But it can operate only one operation at a given location, so the number of locations is what constrains the number of units it operates using this unit of technology capital. If it has two units of technology capital, it can operate twice as many operations at every location. In this paper, aggregation is carried out and the aggregate production functions for the countries are derived. Our framework interacts well with the national accounts in the same way as does the neoclassical growth model. It also interacts well with the international accounts. There are constant returns to scale, and therefore no monopoly rents. Yet there are gains to being economically integrated. In the framework, a country’s openness is measured by the effect of its policies on the productivity of foreign operations. Our analysis indicates that there are large gains to this openness.

Here we reply to Robert Solow’s comment on our work, Modern Macroeconomics in Practice: How Theory is Shaping Policy.

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.

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.

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.

The possibility of regime shifts in monetary policy can have important effects on rational agents’ expectation formation and equilibrium dynamics. In a DSGE model where the monetary policy rule switches between a dovish regime that accommodates inflation and a hawkish regime that stabilizes inflation, the expectation effect is asymmetric across regimes. Such an asymmetric effect makes it difficult, but still possible, to generate substantial reductions in the volatilities of inflation and output as the monetary policy switches from the dovish regime to the hawkish regime.

In the data, a sizable fraction of price changes are temporary price reductions referred to as sales. Existing models include no role for sales. Hence, when confronted with data in which a large fraction of price changes are sales related, the models must either exclude sales from the data or leave them in and implicitly treat sales like any other price change. When sales are included, prices change frequently and standard sticky price models with this high frequency of price changes predict small effects from money shocks. If sales are excluded, prices change much less frequently and a standard sticky price model with this low frequency of price changes predict much larger effects of money shocks. This paper adds a motive for sales in a parsimonious extension of existing sticky price models. We show that the model can account for most of the patterns of sales in the data. Using our model as the data generating process, we evaluate the existing approaches and find that neither well approximates the real effects of money in our economy in which sales are explicitly modeled.

There is a large amount of intermediated borrowing and lending between households. Some of it is intergenerational, but most is between older households. The average difference in borrowing and lending rates is over 2 percent. In this paper, we develop a model economy that displays these facts and matches not only the returns on assets but also their quantities. The heterogeneity giving rise to borrowing and lending and differences in equity holdings depends on differences in the strength of the bequest motive. In equilibrium, the lenders are annuity holders and the borrowers are those who have equity holdings, who live off its income when retired, and who leave a bequest. The borrowing rate and return on equity are the same in the absence of aggregate uncertainty. The divergence between borrowing and lending rates can thus give rise to an equity premium, even in a world without aggregate uncertainty.

This paper describes a simple model of aggregate and firm growth based on the introduction of new goods. An incumbent firm can combine labor with blueprints for goods it already produces to develop new blueprints. Every worker in the economy is also a potential entrepreneur who can design a new blueprint from scratch and set up a new firm. The implied firm size distribution closely matches the fat tail observed in the data when the marginal entrepreneur is far out in the tail of the entrepreneurial skill distribution. The model produces a variance of firm growth that declines with size. But the decline is more rapid than suggested by the evidence. The model also predicts a new-firm entry rate equal to only 2.5% per annum, instead of the observed rate of 10% in U.S. data.