Political influence on historical ESA listings by state: a count data analysis

We use count data analysis to examine the influence that a state’s congressional subcommittee representation (with oversight of the US Fish and Wildlife Service) has on the number of species that are added to the Endangered Species Act (ESA) list in each state each year (1973–2004). Explanatory variables include: (1) ecological—species type, NatureServe’s “at-risk” assessment, federal land area, rainfall, and coastal location; (2) demographic—population density, hunting/fishing participation, and farming area; (3) political—League of Conservation Voters’ environmental scores and party affiliation. “Pro-environment” (“pro-development”) representatives appear to have increased (reduced) ESA listings in their states.