Sunday, December 16, 2012

Sở hữu súng và tỷ lệ giết người/tử vong

Nhân thảm họa xả súng ở trường mẫu giáo thị trấn Newton, bang Connecticut, tôi có tìm lại những nghiên cứu kinh tế, xã hội và y học về ảnh hưởng của việc cho phép sở hữu súng. Nhắc lại hai quan điểm về sở hữu súng: Sở hữu súng tạo điều kiện để tội phạm có súng, nhưng việc người dân thường có súng sẽ có tác dụng ngăn ngừa tội phạm. Còn đây là một số nghiên cứu thực nghiệm dựa vào data:

- Trang wiki về số lượng súng theo từng nước: http://en.wikipedia.org/wiki/Number_of_guns_per_capita_by_country. Trang này sử dụng dữ liệu từ Small Arms Survey.
- Ba bài báo trên AER Papers & Proceedings năm 1998:
Bronars Lott: http://www.jstor.org/discover/10.2307/116970?uid=3738016&uid=2134&uid=2&uid=70&uid=4&sid=21101496390801
Dezhbakh Rubin: http://www.jstor.org/discover/10.2307/116970?uid=3738016&uid=2134&uid=2&uid=70&uid=4&sid=21101496332111
Glaeser Glendon: http://www.jstor.org/discover/10.2307/116967?uid=3738016&uid=2134&uid=2&uid=70&uid=4&sid=21101496390801

McDowall Lizotte Wiersema:
It has often been argued that civilian firearm ownership acts as a deterrent to crime. Much of the support for this claim is based on incidents that have called attention to the prevalence of privately owned guns. We examined several such incidents and failed to and persuasive evidence of a deterrent effect.

Cook Leitzel:
http://www.jstor.org/discover/10.2307/1192211?uid=3738016&uid=2134&uid=2&uid=70&uid=4&sid=21101496390801

Kwon et al
The purpose of this study is to statistically and empirically evaluate the effectiveness of the gun control laws that have been adopted by states and municipalities. States are divided into two groups: states with no restrictions as to gun use and states with restrictions (e.g., waiting periods, license, etc.). Multiple linear regression models are used to evaluate the relationship between the number of gun related deaths in 1990 and sets of determinants which include state laws and regulations governing the use of firearms. The study results indicate that gun control laws have a very mild effect on the number of gun related deaths while socioeconomic variables such as a state's poverty level, unemployment rate and alcohol consumption, have significant impact on firearm related deaths. These findings suggest that any reduction in resources spent on social programs tied to the Crime Bill may be counter-productive.

Killiashttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC1485564/?page=1

Update: Có lẽ bài này của Mark Duggan quan trọng nhất (JPE 2001).
This paper examines the relationship between gun ownership and crime. Previous research has suffered from a lack of reliable data on gun ownership. I exploit a unique data set to reliably estimate annual gun ownership rates at both the state and the county level during the past two decades. My findings demonstrate that changes in gun ownership are significantly positively related to changes in the homicide rate, with this relationship driven entirely by the impact of gun ownership on murders in which a gun is used. The effect of gun ownership on all other crime categories is much less marked. Recent reductions in the fraction of households owning a gun can explain at least one-third of the differential decline in gun homicides relative to non-gun homicides since 1993. I also use this data to examine the impact of Carrying Concealed Weapons legislation on crime, and reject the hypothesis that these laws led to increases in gun ownership or reductions in criminal activity.