Defenders of Wildlife analyzes ESA in Proceedings of the National Academy of Sciences
"In contrast to conventional wisdom about section 7 implementation, no project was stopped or extensively altered as a result of FWS finding jeopardy or adverse modification during this period. We also show that median consultation duration is far lower than the maximum allowed by the Act...The results discredit many of the claims about the onerous nature of section 7 but also raise questions as to how federal agencies could apply this tool more effectively to conserve species."
http://www.pnas.org/content/early/2015/12/01/1516938112
