Concealed Carry Laws Decrease Violent Crime

Research by Prof. Ayres and Donahue Consensus & Replication of Research NRC Research NBER Working Paper Series (ADZ) Conclusion References 1. Why is Prof. Lott"s research, at best, inclusive; at worst, incorrect. (a) Flaw I: Missing of Incarceration Rate Although in his book, Prof. Lott includes more than thirty-two variables considered to be influential on the national criminal, incarceration rate, mysteriously, escaped Prof. Lott"s attentions. In their 2009 Report, Prof. Ayres and Prof. Donohue explicitly criticized Prof. Lott by stating that: "Yet how much confidence can we really in the Lott and Mustard specification given that, in addition to its other infirmities, it does not even include a variable known to be a powerful factor in reducing crime - the incarceration rate (Marvell and Moddy 1994; Levitt 1996)? If the incarceration rate, conspicuously missing from Prof. Lott"s report, is correlated with the presence of CCW, the resulting estimates on the impact of these laws would be marred by omitted variable bias. [1] Therefore it is conceivable that CCW may perhaps be ineffective (or may even increase the crime) while other more prevailing factors drive down the overall national criminal rates. (b) Flaw II: Missing of Crack Cocaine movement in late 1980s and early 1990s. The rise of the crack cocaine phenomenon, a factor unaccounted for in Prof. Lott"s research, according to many well respected researches, had a powerful effect in increasing murders in the United States in the late 1980s and early 1990s. The national criminal rate dropped dramatically following the events. Given the fact that, during the same period, the numbers of permits is on the rise, it is therefore not unreasonable to assume that "what some of the early paper deemed to be a benefit of passing CCW in reducing murder may well be the effect of crack"s harmful impact on murder in states that chose not to adopt CCW, such as New York and California. " [1] 2. Research by Prof. Ayres and Donahue Pro invalidated Prof. Ayres and Donahue"s study on two separate grounds: first he suggested that Prof. Ayres and Donahue"s results have yet been replicated, thereby implying that their research may perhaps be questionable. Second, Pro suggested that permit holders are extremely law abiding thereby insinuating that their research must be based on some implausible assumptions. I will be addressing his assertions in a reversed order. (a) Implausible Assumptions (a1) Observations Permit holders, although appear to be more law abiding than the general population, have done quite a bit of harm. According to Ms. Rand, the spokesman for the Violence Policy Center, "130 (2010 figure) civilians and nine police officers have been killed and 13 mass shootings have been carried out by people with concealed-weapons permits since May 2007. " [2] Some more recent incidents include Colorado theater shooting which left at least 12 dead, and 59 injured. Mr. James Hoimes, the alleged suspect, obtained his weapon legally. [3] (a2) Theoretical Explanation - Two possible explanations First, it is plausible to assume that the majority of permit holders are law-abiding citizens while only a few permit holders involve in violent crime because of CCW (easy access to weapons). In this scenario, as long as the percentage of increase in total number of permit holders is greater than the percentage of increase in number of criminals with permits, the overall criminal rate among permit holders would be on decline while the CCW may lead to increase in violent crime. Taken mathematically, let"s assume that we have: Number of Crimes perpetrated by Permit Holders (hereinafter Number of Crimes) Criminal Rate among Permit Holders (hereinafter Criminal Rate) Prior to CCW Number of Permit holders: 100 Number of Crimes: 10 Criminal Rate: 10% After CCW Number of Permit holder: 200 (+100%) Number of Crimes: 15 (+ 50%) Criminal Rate: 7.5% (- 2.5%) Permits holder may increase 100% while criminal rate may decrease by 2.5% even If number of crimes increase by 50% because of CCW. Second, CCW may result in more violences among non-permit holders. For instance, a delusional sense of security may lead permit holders to engage in some unnecessary provocative behaviors when confronting criminals; moreover, non-permit holders may obtain weapons via permit holders. 3. Consensus & Replication of Research In the field of statistical studies, the similar results obtained by other researchers, providing that they use the exact same regressions models, cannot be used to vouch for the accuracy of one"s research. Please consider the following example: Assume that we attempt to design a regression model to explain a particular phenomenon, and we impudently assume that A1=A2 in our modeling design. The assumption is therefore built into our models. By utilizing the exact same models and dataset, other researchers may reach the similar results even if it is implausible to assume that A1=A2. The similar result thus, can only be used to prove that there is no calculation error; it cannot confirm the accuracy of the model itself, which remains contentious among peers. Source No.7 in Pro"s argument may make the similar mistake. By using a more comprehensive regression model (adding two specifications: incarceration rate and crack cocaine phenomenon), Prof. Ayres and Prof. Donahue"s research an opposite conclusion: CCW may increase crime. 4. NRC Research If 17 out of 18 panel members (about 95%) conclude that there is no existing credible research that could conclude CCW increased or decreased crime, it would be constituting a implicit rejection of Prof. Lott"s findings. With only one member dissented from the majority opinion, it is highly likely that the dissent opinion is inaccurate or biased. Dr. Wlison erred in excluding incarceration rate and crack cocaine phenomenon as Prof. Lott did, thereby rendering his analysis biased by omitting imperative variables. [1] NBER Working Paper Series (ADZ) According to Pro"s source, "it is the change in the specification, not these errors in the ADZ data set that prevented them from the NRC estimates. " Therefore, it is not unreasonable to assume that these errors may not lead to a dramatic change in NBER"s conclusion. Given the fact that the errors are non-essential to the conclusion, people should be expected to accept NBER"s conclusion, which asserts that CCW may increase crime. 6. Conclusion In analyzing the purportedly relationships between CCW and crime, Prof. Lott"s omission of key variables renders his study dubious, if not spurious. By adopting a more comprehensive model, Prof. Ayres and Prof. Donohue are able to reach a conclusion that CCW may lead to an increase in crime. NBER report further strengthens this position while NRC report is somewhat more equivocate on the matter, albeit 17 of 18 panel members implicitly renounced Prof. Lott"s findings. Although there is much to be done to affirm the relation between CCW and crime, there is a sufficient body of evidence to suggest that CCW does not lead to decrease in crime, if not necessarily increase it. Thank you. References [1]. . http://works.bepress.com... [2]. . http://www.msnbc.msn.com.../ [3]. . http://www.foxnews.com...