Insurers' Carbon Underwriting Policies

We study the determinants, structure, implementation, and effects of carbon underwriting policies among the world’s largest insurers. Adoption is more common among European insurers and less so among specialty and unlisted firms, with coal policies preceding those for oil and gas. Using novel mine-insurance data, we show that implementation is often incomplete, and some insurers expand coal coverage despite commitments. On average, insurers reduce the number of insured mines by 16%, insured coal volumes by 56%, and make continued coverage 13pp less likely. Affected mines are more likely to be abandoned and experience constrained operations.