Knowledge that Transforms

In recent decades, growth of world trade has been driven largely by rapid growth of trade in intermediate inputs. Much of input trade involves multinational firms locating input processing in their foreign affiliates, thereby creating global vertical production networks. We use firm-level data on U.S. multinationals to examine trade in intermediate inputs for further processing between parent firms and their foreign affiliates. Among our main findings are that demand for imported inputs is higher when affiliates face lower trade costs, lower wages for less-skilled labor, and lower corporate income tax rates.

Knowledge flows within and across countries may have important consequences for both productivity and innovation. We use data on 1.5 million patents and 4.5 million citations to estimate knowledge flows at the frontier of technology across 147 subnational regions during 1975-1996 within the frame of a gravity-like equation. We estimate that only 20% of average knowledge is learned outside the average region of origin, and only 9% is learned outside the country of origin. However, knowledge in the computer sector flows substantially farther, as does knowledge generated by technological leaders. In comparison with trade flows, we see that knowledge flows reach much farther. External accessible R&D gained through these flows has a strong positive effect on innovative activity for a panel of 113 European and North American regions over 22 years.

Previous studies, relying on short-term averages of fathers' earnings, have estimated the intergenerational elasticity (IGE) in earnings to be approximately 0.4. Due to persistent transitory fluctuations, these estimates have been biased down by approximately 30% or more. Using administrative data containing the earnings histories of parents and children, the IGE is estimated to be around 0.6. This suggests that the United States is substantially less mobile than previous research indicated. Estimates of intergenerational mobility are significantly lower for families with little or no wealth, offering empirical support for theoretical models that predict differences due to borrowing constraints.

We seek to contribute to the debate over globalization and the environment by asking: What is the effect of trade on a country's environment, for a given level of GDP? We take specific account of the endogeneity of trade, using exogenous geographic determinants of trade as instrumental variables. We find that trade tends to reduce three measures of air pollution. Statistical significance is high for concentrations of SO2, moderate for NO2, and lacking for particulate matter. Although results for other environmental measures are not as encouraging, there is little evidence that trade has a detrimental effect on the environment.

Using a new data set on annual deaths from disasters in 73 nations from 1980 to 2002, this paper tests several hypotheses concerning natural-disaster mitigation. Though richer nations do not experience fewer natural disasters than poorer nations, richer nations do suffer less death from disaster. Economic development provides implicit insurance against nature's shocks. Democracies and nations with higher-quality institutions suffer less death from natural disaster. Because climate change is expected to increase the frequency of natural disasters such as floods, these results have implications for the incidence of global warming.