A bird's-eye view: firm biodiversity footprints and earnings expectations
Using bird-watching data matched to U.S. industrial facilities, I show that facility construction causally reduces local bird populations and species, and I build a firm-level biodiversity footprint index from these estimates. Firms with large footprints face persistently higher production costs, which investors initially misread as operational decline. The resulting pessimism corrects around earnings announcements, generating predictable returns.
Best PhD Paper Award, Global Research Alliance for Sustainable Finance and Investment 2025 (for an earlier version)
Abstract
Using bird-watching data matched to U.S. industrial facilities, I show that firms causally reduce bird populations and species. I use these estimates to construct a firm-level biodiversity footprint index that identifies firms with many ecologically consequential facilities relative to their size. Sorting on the footprint generates significant abnormal returns among small- and mid-cap firms from 1988 to 2024. The return premium reflects forecast errors: investors misinterpret the higher production costs of high-footprint firms as operational decline, and their pessimism corrects when earnings are announced. Although firms' facility locations are public, firms with larger biodiversity footprints provide less voluntary biodiversity information.