Abstract

Many studies have sought to explain the major crime declines experienced in most advanced countries. Key hypotheses relate to: lead poisoning; abortion legalization; drug markets; demographics; policing numbers and strategies; imprisonment; strong economies; the death penalty; gun control; gun concealment; immigration; consumer confidence; the civilizing process, and; improved security. This paper outlines five tests that a hypothesis should pass to be considered further. It finds that fourteen of the fifteen hypotheses fail two or more tests. The security hypothesis appears to pass the tests, and thereby pave the way for further research.