Policies to mitigate global climate change entail significant economic costs. Yet a growing number of firms lobby in favor of regulation to mitigate carbon emissions. Why do firms support environmental regulations that directly increase production costs? This question is all the more puzzling in a globalized economy where regulation may undermine the competitiveness of domestic firms at home and abroad. By imposing differential costs on participants in the domestic market, policies designed to mitigate carbon emissions shift market share toward firms with low anticipated adjustment costs. I develop and test a model of climate change policymaking in the presence of market competition and open borders. Heterogeneity in adjustment costs induces a preference for regulation among low-cost firms. Firms facing import pressure—or export competition—may prefer stringent regulation if costs are sufficiently asymmetric. Firms embedded in global value chains also benefit if regulation raises the costs of domestically produced intermediate goods.
