Gun Prevalence, Homicide Rates and Causality: A GMM Approach to Endogeneity Bias
The positive correlation between gun prevalence and homicide rates has been widely documented. But does this correlation reflect a causal relationship? This study seeks to answer the question of whether more guns cause more crime, and unlike nearly all previous such studies, we properly account for the endogeneity of gun ownership levels. We discuss the three main sources of endogeneity bias - reverse causality (higher crime rates lead people to acquire guns for self-protection), mismeasurement of gun levels, and omitted/confounding variables - and show how the Generalized Method of Moments (GMM) can provide an empirical researcher with both a clear modeling framework and a set of estimation and specification testing procedures that can address these problems. A county level cross-sectional analysis was performed using data on every US county with a population of at least 25,000 in 1990; the sample covers over 90% of the US population in that year. Gun ownership levels were measured using the percent of suicides committed with guns, which recent research indicates is the best measure of gun levels for cross-sectional research. We apply our procedures to these data, and find strong evidence of the existence of endogeneity problems. When the problem is ignored, gun levels are associated with higher rates of gun homicide; when the problem is addressed, this association disappears or reverses. Our results indicate that gun prevalence has no significant net positive effect on homicide rates: ceteris paribus, more guns do not mean more crime.
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- Jean-Marie Dufour, 2003.
"Identification, Weak Instruments and Statistical Inference in Econometrics,"
CIRANO Working Papers
- Jean-Marie Dufour, 2003. "Identification, weak instruments, and statistical inference in econometrics," Canadian Journal of Economics, Canadian Economics Association, vol. 36(4), pages 767-808, November.
- DUFOUR, Jean-Marie, 2003. "Identification, Weak Instruments and Statistical Inference in Econometrics," Cahiers de recherche 2003-12, Universite de Montreal, Departement de sciences economiques.
- Nicholas J. Cox, 1998. "WINSOR: Stata module to Winsorize a variable," Statistical Software Components S361402, Boston College Department of Economics, revised 09 Aug 2006.
- Christopher F Baum & Mark E. Schaffer & Steven Stillman, 2003.
"Instrumental variables and GMM: Estimation and testing,"
StataCorp LP, vol. 3(1), pages 1-31, March.
- Christopher F Baum & Mark E. Schaffer & Steven Stillman, 2002. "Instrumental variables and GMM: Estimation and testing," Boston College Working Papers in Economics 545, Boston College Department of Economics, revised 14 Feb 2003.
- Christopher F Baum & Mark E. Schaffer & Steven Stillman, 2002. "Instrumental variables and GMM: Estimation and testing," United Kingdom Stata Users' Group Meetings 2003 02, Stata Users Group.
- Christopher F Baum & Mark E. Schaffer & Steven Stillman, 2002. "Instrumental variables and GMM: Estimation and testing," North American Stata Users' Group Meetings 2003 05, Stata Users Group.
- DUFOUR, Jean-Marie, 2003. "Identification, Weak Instruments and Statistical Inference in Econometrics," Cahiers de recherche 10-2003, Centre interuniversitaire de recherche en économie quantitative, CIREQ.
- Deborah Azrael & Philip J. Cook & Matthew Miller, 2001. "State and Local Prevalence of Firearms Ownership: Measurement, Structure, and Trends," NBER Working Papers 8570, National Bureau of Economic Research, Inc.
- Lawrence Southwick, 1997. "Do guns cause crime? Does crime cause guns? A granger test," Atlantic Economic Journal, International Atlantic Economic Society, vol. 25(3), pages 256-273, September.
- Jinyong Hahn & Jerry Hausman, 2003. "Weak Instruments: Diagnosis and Cures in Empirical Econometrics," American Economic Review, American Economic Association, vol. 93(2), pages 118-125, May.
- Mark Duggan, 2000.
"More Guns, More Crime,"
NBER Working Papers
7967, National Bureau of Economic Research, Inc.
- Donald W.K. Andrews & James H. Stock, 2005.
"Inference with Weak Instruments,"
Cowles Foundation Discussion Papers
1530, Cowles Foundation for Research in Economics, Yale University.
- Christopher F Baum & Mark E Schaffer & Steven Stillman, 2002. "IVREG2: Stata module for extended instrumental variables/2SLS and GMM estimation," Statistical Software Components S425401, Boston College Department of Economics, revised 09 Feb 2015.
- Ruddell, Rick & Mays, G. Larry, 2005. "State background checks and firearms homicides," Journal of Criminal Justice, Elsevier, vol. 33(2), pages 127-136.
- Carlisle E. Moody & Thomas B. Marvell, 2005. "Guns and Crime," Southern Economic Journal, Southern Economic Association, vol. 71(4), pages 720-736, April.
- Moody, Carlisle E, 2001. "Testing for the Effects of Concealed Weapons Laws: Specification Errors and Robustness," Journal of Law and Economics, University of Chicago Press, vol. 44(2), pages 799-813, October.
- Douglas Staiger & James H. Stock, 1997.
"Instrumental Variables Regression with Weak Instruments,"
Econometric Society, vol. 65(3), pages 557-586, May.
- Douglas Staiger & James H. Stock, 1994. "Instrumental Variables Regression with Weak Instruments," NBER Technical Working Papers 0151, National Bureau of Economic Research, Inc.
- James H. Stock & Motohiro Yogo, 2002. "Testing for Weak Instruments in Linear IV Regression," NBER Technical Working Papers 0284, National Bureau of Economic Research, Inc.
- Stock, James H & Wright, Jonathan H & Yogo, Motohiro, 2002. "A Survey of Weak Instruments and Weak Identification in Generalized Method of Moments," Journal of Business & Economic Statistics, American Statistical Association, vol. 20(4), pages 518-29, October.
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