More Guns, Less Crime
More Guns, Less Crime is a book by John R. Lott Jr. that says violent crime rates go down when states pass "shall issue" concealed carry laws. He presents the results of his statistical analysis of crime data for every county in the United States during 29 years from 1977 to 2005. Each edition of the book was refereed by the University of Chicago Press. The book examines city, county and state level data from the entire United States and measures the impact of 13 different types of gun control laws on crime rates. The book  expands on an earlier study published in 1997 by Lott and his co-author David Mustard in "The Journal of Legal Studies" and by Lott and his co-author John Whitley in "The Journal of Law and Economics", October 2001. Main topics. Below are summaries of the main topics discussed in "More Guns, Less Crime". Shall issue laws. Lott examines the effects of shall issue laws on violent crime across the United States. His conclusion is that shall issue laws, which allow citizens to carry concealed weapons, steadily decrease violent crime. He explains that this result makes sense because criminals  are deterred by the risk of attacking an armed victim. As more citizens arm themselves, the danger to criminals increases. Training requirements. Lott examines the effects of training requirements on crime rate and accident rate. He finds that training requirements have very little effect on both crime rates and accident rates. Waiting periods. Lott examines the effects of waiting periods. These include limiting the time before purchasing a gun, and limiting the time before obtaining a concealed carry permit. Brady Law. Lott examines the effects of the Brady law. Section::::"Stand Your Ground" and "Castle Doctrine" Laws. The third edition of  the book is the first study to examine Stand Your Ground and Castle Doctrine laws. Other countries. The focus of the book is overwhelmingly on the US, but Lott does mention briefly gun ownership and crime rates in other countries, such as Great Britain, Ireland, and Jamaica, noting that murder rates rose after guns were banned. He also notes that many countries, such as Switzerland, Finland, New Zealand, and Israel, have high gun ownership rates and low crime rates, while many other countries have both low gun ownership rates and either high or low crime rates. Reception. NRC Report. Partially  in response to Lott's book, a sixteen-member panel of the United States National Research Council was convened to address the issue of whether right-to-carry laws influenced crime rate. They also looked at many other gun control measures, including the soon-to-expire 1994 Assault Weapon Ban, gun buy-backs, and bans on handgun possession or carry. In 2004 they issued the report "Firearms and Violence: A Critical Review" which examined Lott's statistical methods in detail, including computation of the statistical uncertainties involved, and wrote The committee found that answers to some of the most pressing  questions cannot be addressed with existing data and research methods, however well designed. Indeed, the committee was unable to find any of the laws that it examined had any effect on crime or suicide rates. In the case of right-to-carry laws, despite a large body of research, the committee found no credible evidence that the passage of right-to-carry laws decreases or increases violent crime, and there is almost no empirical evidence that the more than 80 prevention programs focused on gun-related violence have had any effect on children's behavior, knowledge, attitudes, or beliefs  about firearms. The committee found that the data available on these questions are too weak to support unambiguous conclusions or strong policy statements. The council determined that Lott's data-sets can be subject to manipulation given a number of factors, so that different studies produce different results. "While the trend models show a reduction in the crime growth rate following the adoption of right-to-carry laws, these trend reductions occur long after law adoption, casting serious doubt on the proposition that the trend models estimated in the literature reflect effects of the law change." The issue of right -to-carry laws was the only law that drew a dissent from the committee's otherwise universal findings that it could not reach a conclusion. In a very unusual dissent for National Research Council reports, criminologist James Q. Wilson wrote that The direct evidence that such shooting sprees occur is nonexistent. The indirect evidence, as found in papers by Black and Nagin and Ayres and Donohue [cited in Chapter 6], is controversial. Indeed, the Ayres and Donohue paper shows that there was a "statistically significant downward shift in the trend" of the murder rate (Chapter 6, page 135). This suggests  to me that for people interested in RTC laws, the best evidence we have is that they impose no costs but may confer benefits. ... In sum, I find that the evidence presented by Lott and his supporters suggests that RTC laws do in fact help drive down the murder rate, though their effect on other crimes is ambiguous. Support. A conference organized by the Center for Law, Economics, and Public Policy at Yale Law School and held at American Enterprise Institute was published in a special issue of "The Journal of Law and Economics". Academics of all interests in the  debate were invited to participate and provide refereed empirical research. As follows are some papers from that conference supported Lott's conclusions. Other refereed empirical academic studies besides the original paper with David Mustard that have supported Lott's conclusions include the following. Opposition. Some academic studies that have rejected Lott's conclusions include the following. Virtually all of these studies contend that there seems to be little or no effect on crime from the passage of license-to-carry laws. One by Ayres and Donohue, published in 2003, finds a temporary increase in aggravated assaults. Editions. There have been  three editions of "More Guns, Less Crime: Understanding Crime and Gun Control Laws," all published by University of Chicago Press: