Samuel Kortum

Unilateral Carbon Taxes, Border Tax Adjustments, and Carbon Leakage

We examine the impact of a unilateral carbon tax in developed countries, focusing on the expected size of carbon leakage (an increase in emissions in non-taxing regions as a result of the tax) and the effects on leakage of border tax adjustments. We start by analyzing the problem using a simple two-country, three-good general equilibrium model to develop intuitions. We then simulate the expected size of the effects using a new, open-source, computable general equilibrium (CGE) model. We analyze the extent of emissions reductions from a carbon tax in countries that made commitments under the Kyoto Protocol (Annex B countries), the expected carbon leakage, and the effects of border tax adjustments on carbon leakage, all relative to our baseline projections for emissions. We also perform extensive sensitivity tests on the parameters of the CGE model. Finally, we consider the effects of imperfect border tax adjustments on leakage, such as global or regional schedules of border taxes.

A Rising Tide Raises All Ships: Trade and Diffusion as Conduits of Growth

Measures of innovative activity show it to be concentrated in a small number of countries. Yet the benefits of innovation are experienced broadly. International trade is one conduit through which the benefits of innovation in one country can flow abroad. Technological diffusion is another. In this paper we develop a model of technology and trade to explore these alternatives. An implication of the model is that increased trade will itself affect observed productivity as well as real wages. We analyse data on trade, research, and productivity from five major industiral economies in light of the model. Trade alone can explain observed cross-sectional patterns of innovation and productivity quite well. Nonetheless, trade fails to explain why productivity growth is as high in countries where less inventive activity occurs. An implication is that diffusion rather than trade is responsible for the similarity in growth rates across major industrial countries.

The value of microprocessor designs

Applying a centuries-old technique to modern cost estimation.

Chapter 3 Patents and Information Diffusion

Patent data have been exploited to track invention and international technology diffusion. We review evidence on research activity, international patenting, and income differences across countries. Guided by that evidence, we construct a model of ideas in the world economy that includes the decision of whether and where to patent them. The model makes precise connections between international patent statistics and cross-country differences in innovation, technology diffusion, market size, and strength of patent protection. We use it to organize our discussion of existing empirical studies, which typically focus on one of five core relationships: (i) national pools of knowledge and international spillovers from basic research; (ii) aggregate productivity and international technology diffusion from applied research; (iii) international patenting and the production of ideas, international diffusion, market sizes, and intellectual property regimes; (iv) the value of ideas and diffusion, market sizes, and the intellectual property regimes; or (v) investment in research and research productivity, the cost of research, and the value of ideas. While distinguishing between these five relationships proves useful, they are, of course, logically intertwined. Taking these interconnections into account will contribute to the goal of building a quantitative model of the creation, diffusion, and adoption of ideas in the global economy.