1. Ashby, N., & Sobel, R. (2008). Income inequality and economic freedom in US states. Public Choice, 134(3–4), 329–346.
2. Becker, G. (1968). Crime and punishment: an economic approach. Journal of Political Economy, 76(2), 169–217.
3. Bureau of Justice Statistics. (2002). Recidivism of prisoners released in 1994. Washington: US Department of Justice.
4. Bureau of Justice Statistics. (Various years). Annual parole surveys. Washington: US Department of Justice.
5. Campbell, N., Heriot, K., & Jauregui, A. (2008). Housing prices and economic freedom. Journal of Private Enterprise, 23(2), 1–17.