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 SO 2 , moderate for NO 2 , 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.

We develop a procedure to rank-order objects using censored panel data sets. We illustrate this by ranking countries and commodities using disaggregated American import data and find evidence that countries and commodities can be ranked. Countries habitually begin to export goods to the United States according to an ordering; goods are also exported in order. We estimate these orderings using a methodology, that takes account of the fact that most goods are not exported by most countries in our sample. Our orderings seem sensible, robust, and intuitive, and they are correlated with macroeconomic phenomena such as productivity and growth rates.