Li and Zhou (2017) showed that U.S. manufacturing plants release less toxic emissions when their parent firms import more from low-wage countries (LWCs), consistent with pollution offshoring — but they could not tell whether this home-country cleanup reflects a genuine global environmental improvement or displacement of pollution to the source countries. This record states the open question they left: quantify the net environmental impact of increased developed-country firm sourcing from LWCs on pollution within those LWCs, disentangling pollution-expansion from cleaner-technology-transfer effects, separating in-house offshoring (foreign subsidiaries) from arm's-length outsourcing, and testing whether firms that adopt single stringent global environmental standards engage less in pollution offshoring. The home-country result has since been replicated in Japan and France, with partial host-country evidence for each channel separately, but no study is known to resolve the net question.

Background

Offshoring is a firm's relocation of production stages to another country, either within its own foreign subsidiaries (in-house offshoring, a form of foreign direct investment) or through contracts with unaffiliated foreign suppliers (arm's-length offshore outsourcing). The Pollution Haven Hypothesis (PHH) predicts that polluting activities concentrate in countries with weak environmental regulation; its empirical magnitude has been debated for decades, and the field's standard analytical tool — the scale–composition–technique decomposition of Copeland and Taylor (1994), which separates a pollution-expansion effect (scale and composition) from a cleaner-technology, or technique, effect — treats firm-level evidence as the missing ingredient. 'Pollution offshoring' is the firm-strategy variant of this question: a firm keeps clean, high-value stages at home while sourcing pollution-intensive stages from abroad. Li and Zhou (2017) provided the first firm-level evidence for the United States: linking U.S. plant-level toxic emissions (from the Toxics Release Inventory, the U.S. registry of industrial releases of toxic chemicals) to their parents' imports from low-wage countries (LWCs), and using an instrumental-variable strategy (variables constructed from Chinese export-supply shocks to other OECD countries to isolate exogenous variation in U.S. firms' sourcing), they found that U.S. plants emit less when their parent imports more from LWCs, that goods sourced from LWCs are in more pollution-intensive industries, and that plants shift toward less pollution-intensive production and spend less on pollution abatement. Berry, Kaul and Lee (2021) confirmed a pollution haven effect in global sourcing decisions: countries with more stringent environmental standards receive smaller shares of U.S. imports, both for sourcing from owned foreign operations and from unrelated third parties. The critical unresolved issue is that all of this evidence is measured on the home (developed-country) side. Whether the observed cleanup is real decontamination or mere displacement cannot be decided without observing pollution at the foreign production sites, where two countervailing forces operate: expansion of pollution-intensive production (worse global outcomes) and transfer of cleaner technologies and management practices that reduce pollution per unit produced (the pollution halo). The review by Cole, Elliott and Zhang (2017) documents that the foreign-direct-investment-and-environment literature — the natural home for the second question — remains mixed on exactly this halo-versus-haven point and explicitly calls for firm-level studies, noting environmental outsourcing as the newer, even less studied alternative.

Problem Statement

Determine the net environmental impact of increased sourcing by developed-country firms (in the source study, U.S. firms) from low-wage countries (LWCs) on pollution within those low-wage countries, and how firm strategy shapes it. Concretely, following Li and Zhou's (2017) open questions: (1) quantify the net effect of buyer firms' increased LWC sourcing on pollution at the foreign production sites, disentangling the countervailing pollution-expansion effect (more pollution-intensive production overseas) from the technique effect (transfer of cleaner technologies and practices reducing pollution per unit) — which requires plant- or facility-level pollution and technology-adoption data in LWCs rather than U.S. industry pollution intensities used as proxies; (2) separate the environmental consequences and attribution of responsibility between in-house offshoring (production in foreign subsidiaries) and arm's-length outsourcing to independent foreign contractors; and (3) test whether firms that commit to a single stringent global environmental standard, rather than country-specific standards, engage less in pollution offshoring. These three questions serve one overarching objective: establishing whether firm-level pollution offshoring merely displaces pollution across borders or changes net global pollution, and which firm strategies and governance modes condition the answer. An answer must observe pollution outcomes at foreign production sites (or direct measures of foreign industry or facility pollution intensity), not only home-country emissions, and must identify the causal effect of buyer sourcing rather than pure selection of suppliers.

References

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