Innovation, firm dynamics, and international trade

We present a general equilibrium model of the decisions of firms to innovate and to engage in international trade. We use the model to analyze the impact of a reduction in international trade costs on firms' process and product innovative activity. We first show analytically that if all firms export with equal intensity, then a reduction in international trade costs has no impact at all, in steady-state, on firms' investments in process innovation. We then show that if only a subset of firms export, a decline in marginal trade costs raises process innovation in exporting firms relative to that of non-exporting firms. This reallocation of process innovation reinforces existing patterns of comparative advantage, and leads to an amplified response of trade volumes and output over time. In a quantitative version of the model, we show that the increase in process innovation is largely offset by a decline in product innovation. We find that, even if process innovation is very elastic and leads to a large dynamic response of trade, output, consumption, and the firm size distribution, the dynamic welfare gains are very similar to those in a model with inelastic process innovation.

Aggregate implications of innovation policy

In this paper we present a tractable model of innovating firms and the aggregate economy that we use to assess quantitatively the link between the responses of firms to changes in innovation policy and the impact of those policy changes on aggregate output and welfare. We show that, to a first-order approximation, a wide range of policy changes have a long-run impact in direct proportion to the fiscal expenditures on those policies, and that to evaluate the aggregate impact of a policy change, there is no need to calculate changes in firms' decisions in response to these policy changes. ; We use these results to compare the relative magnitudes of the impact on aggregates in the long run of three innovation policies in the United States: the Research and Experimentation Tax Credit, federal expenditure on R&D, and the corporate profits tax. We argue that the corporate profits tax is a relatively important policy through its negative effects on innovation and physical capital accumulation. We also use a calibrated version of our model to examine the absolute magnitude of the impact of these policies on aggregates. We show that, depending on the magnitude of spillovers, it is possible for changes in innovation policies to have very large impact on aggregates in the long run. However, over a 15-year horizon, the impact of changes in innovation policies on aggregate output is not very sensitive to the magnitude of spillovers. ; On the basis of these results we conclude that, while it is possible to make comparisons about the relative importance of different policies and sharp predictions about their aggregate impact in the medium term, it is very difficult to shed much light on the implications of innovation policies for long-run aggregate outcomes and welfare in the absence of direct quantitative evidence on the magnitude of spillovers.

The transition to a new economy after the Second Industrial Revolution

During the Second Industrial Revolution, 1860–1900, many new technologies, including electricity, were invented. After this revolution, however, several decades passed before these new technologies diffused and measured productivity growth increased. We build a quantitative model of technology diffusion which we use to study this transition to a new economy. We show that the model implies both slow diffusion and a delay in growth similar to that in the data. Our model casts doubt, however, on the conjecture that this experience is a useful parallel for understanding the productivity paradox following the Information Technology Revolution.

Innovation, firm dynamics, and international trade

We present a general equilibrium model of the response of firms' decisions to operate, innovate, and engage in international trade to a change in the marginal cost of international trade. We find that, although a change in trade costs can have a substantial impact on heterogeneous firms' exit, export, and process innovation decisions, the impact of changes in these decisions on welfare is largely offset by the response of product innovation. Our results suggest that microeconomic evidence on firms' responses to changes in international trade costs may not be informative about the implications of changes in these trade costs for aggregate welfare.

Pricing-to-market, trade costs, and international relative prices

International relative prices across industrialized countries show large and systematic deviations from relative purchasing power parity. We embed a model of imperfect competition and variable markups in a quantitative model of international trade. We find that when our model is parameterized to match salient features of the data on international trade and market structure in the US, it can reproduce deviations from relative purchasing power parity similar to those observed in the data because firms choose to price-to-market. We then examine how pricing-to-market depends on the presence of international trade costs and various features of market structure.Purchasing power parity

Money and Exchange Rates in the Grossman-Weiss-Rotemberg Model

We examine the impact of monetary injections in the Grossman-Weiss-Rotemberg Model and show that monetary shocks can lead to nominal exchange rates that are more volatile than inflation, money growth or interest rate differentials. Moreover, movements in real exchange rates following monetary injections can be persistent and nearly as large as movements in nominal exchange rates nominal exchange rates.