2005 Imperial College London review of the available scholarship on the impact of red-light cameras on automotive crashes.
2009 University of Pennsylvania Law School research paper looking at the trade-offs between the two options.
2009 review by the World Bank of methods available for addressing transportation-sector emissions and congestion.
2007 McMaster University survey published in Open Medicine comparing 38 studies that look at outcomes of medical care in the two countries.
2006 metastudy on the effect of prison education programs on recidivism and post-incarceration employment rates.
2008 Harvard, Duke and University of California study on the contributions of highly skilled and educated immigrants to the United States economy.