Volume 4, Issue 2 - The Pollution Haven Hypothesis

This paper contributes to the unresolved issue regarding the effect of economic integration on environmental policymaking. In particular, we discuss the joint impact of trade openness and political stability on environmental policymaking. Our theory predicts that the effect of trade integration on environmental policy is conditional on the degree of political stability. Trade integration affects the stringency of environmental policies due to changes in industry bribery behavior, and the effect is conditional on the degree of political stability. The empirical findings support the theory and are robust to alternative specifications. The stringency enhancing effect on environmental policy of trade integration is greater in politically stable countries.

The Clean Air Act and its subsequent amendments have been lauded as the primary stimulant to the impressive improvement in local air quality in the US since 1970. A key component of these regulations is the New Source Review (NSR) requirement, which includes the contentious stipulation that when an existing plant seeks to modify its operations, the entire plant must comply with current standards for new sources. This requirement was included to improve air quality in dirty areas, and prevent a deterioration of air quality in clean areas. Yet, whether NSR provides the proper plant-level incentives is unclear: there are strong disincentives to undertake major plant modifications to avoid NSR. In our examination of more than 2500 and 2200 plant-level modification decisions and closures, respectively, we find empirical evidence suggesting that NSR retards modification rates, while doing little to hasten the closure of existing dirty plants.

With limited participation in an international climate agreement, standard economic analysis suggests that a unilateral action taken by a group of countries in order to reduce its emissions is likely to be undermined by increases in emissions from other countries (carbon leakage). While analyses of carbon leakage typically have regarded the technology in each country as given, abatement technologies are in reality endogenous, and thus technology development may be affected by environmental policies. We demonstrate that with endogenous technologies and technology diffusion between countries, it is no longer obvious that reduced emissions in some countries will increase emissions in other countries. We identify cases in which reduced emissions in some countries might reduce emissions also in other countries.

This paper examines the composition of bilateral manufacturing trade in terms of its pollution intensity. A growing share of world trade takes place between nations who are members of the same regional trade agreement (RTA). We analyze how the formation of RTAs affects the composition of trade. We focus on whether richer or poorer nations specialize in exporting dirty goods. Using bilateral trade data over the years 1980 to 1997 for 128 nations for 34 manufacturing industries, we document that low-, middle-, and high-income nations differ with respect to their income elasticity in exporting dirty goods. Outside of RTA blocs, we find general support for the pollution haven hypothesis. As a nation’s income rises, its exports of dirty goods decrease relative to its exports of clean goods. When we compare, low-income, middle-income and high-income nations, we find that middle-income nations have the largest dirty trade income elasticity. Participation in a RTA slightly weakens the pollution haven effect observed outside of regional trading blocs. We also document cross-RTA heterogeneity in the composition of trade across 13 major RTAs in our sample.

The current paper addresses the relationship between trade and endogenous pollution levels, with a focus different from the previous literature. The mechanism linking pollution and trade here is that trade policy provides the home government with a credible threat that helps motivate domestic firms to adopt cleaner technologies. This credible threat comes from the fact that the government has a greater incentive to protect a clean industry than to protect a very polluting one. In that sense, the existence of trade helps reduce domestic pollution compared to what would prevail in a situation of autarky. On the other hand, a commitment to free trade would be counterproductive: it removes the government’s ability to credibly threaten lower levels of protection. In fact we show that any trade liberalization hurts the welfare of the home country. In terms of world welfare, moderate trade liberalization is helpful, but only as long as it does not affect the technology choices of the firms. Because committing to lower ‘bounded’ tariffs limits a government’s ability to enforce strict environmental standards, a country that has agreed to tighter tariff limits under the World Trade Organization would, other things equal, be a more likely “pollution haven” than a country with weaker WTO commitments.

U.S. Presidential Executive Order 13141 commits the United States to a careful assessment and consideration of the environmental impacts of trade agreements. The most direct mechanism through which trade liberalization would affect environmental quality in the U.S. is through the composition of industries. Freer trade means greater specialization, increasing the concentration of polluting industries in some countries and decreasing it in others. We begin by documenting the substantial shift in U.S. manufacturing toward cleaner industries from 1972 to 1994. We then use annual industry-level data on imports to the U.S. to examine whether this compositional shift can be traced to the significant trade liberalization that occurred over the same time period, and we conclude that no such connection exists. A shift toward cleaner industries has also occurred among U.S. imports, and we find no evidence that pollution-intensive industries have been disproportionately affected by the tariff changes.

Our paper focuses on the role of endogenous technology and technology spillovers in explaining cross country differences in pollution and the pollution haven effect of international trade. In our North-South trade model, technology is endogenously developed by the North and imitated by the South. Environmental regulators choose national environmental policies by trading off the income gains and the disutility from a rise in pollution. Differences in environmental stringency are entirely driven by differences in investment opportunities and distortions that follow from the difference in intellectual property rights protection. We show that without goods trade and in the absence of technology subsidies, the North imposes more stringent environmental regulation than the South. When opening up to trade, the South experiences a rise in prices for pollution-intensive goods and tends to raise pollution as in a standard trade model. Induced technical change, however, may reverse this pollution haven effect.

The "Pollution Haven Hypothesis" (PHH) is one of the most hotly debated predictions in all of international economics. This paper explains the theory behind the PHH by dividing the hypothesis into a series of logical steps linking assumptions on exogenous country characteristics to predictions on trade flows and pollution levels. I then discuss recent theoretical and empirical contributions investigating the PHH to show how each contribution either questions the logical inevitability, or the empirical significance of one or more steps in the pollution haven chain of logic. Suggestions for future research are also provided.