> Dean, > Is it ok that I put this up in my ftp dir? > > Jeff C.
Sure. Here is a slightly updated version. The text is the same, but the data at the end continues through the latest FBI UCR data available (1992), and the only 1993 number I have managed to glean from newspapers. A missing figure from the early 1960s has also been filled in.
At the end, I also added the abstract and the one data table from Loftin's paper.
Dean
The December 5 issue of the New England Journal of Medicine has a Special Article titled "Effects of Restrictive Licensing of Handguns on Homicide and Suicide in the District of Columbia" by Colin Loftin and others. (NEJM, Vol. 325, Num. 23, p. 1615-20).
Loftin suggests that the District's 1976 restrictive handgun licensing, effectively a ban on new handguns, prevented an average of 47 deaths per year. Inexplicably, the report fails to mention the rapid shrinkage of the District's population, or the rising population of the surrounding community in Maryland and Virginia. When homicides and suicides rates are expressed as per-capita rates, any apparent post-1976 benefit enjoyed by the District vanishes.
The core data of the report shows that the average monthly number of gun-related homicides and suicides dropped significantly in DC after it imposed its handgun ban, whereas non-gun deaths in DC and gun and non-gun deaths in the surrounding MD/VA communities did not drop.
Let me restate that data, but combining gun and non-gun deaths:
Mean numbers of homicides and suicides
per month:
before after change
Homicide
District of Columbia 20.3 16.7 -18%
Maryland and Virginia 8.8 9.1 + 3%
Suicide
District of Columbia 7.0 6.0 -14%
Maryland and Virginia 19.1 20.0 + 5%Note that these are deaths per month, not per-capita rates. The study assured us that there were no significant changes within either group, but did not mention actual population sizes or any growth or shrinkage.
I averaged the populations listed in annual FBI Uniform Crime Reports (UCR) and Census Bureau reports, and found substantial changes in the study areas:
Mean population:
before after change
District of Columbia 740,800 639,200 -14%
Maryland and Virginia 2,197,400 2,596,400 +18%I also added up the homicides reported in the UCR. My pre-ban numbers matched Loftin's figures, but the post-ban numbers show a large discrepancy. I find about 100 fewer homicides within DC and about 80 more in MD/VA than are evident in Loftin's numbers. Here are both sets, but expressed as per-capita rates:
Mean annual homicide and suicide rates,
per 100k residents:
before after change
My homicide count
District of Columbia 32.9 29.9 - 9%
Maryland and Virginia 4.8 4.5 - 6%
Loftin's homicide rates
District of Columbia 32.8 31.3 - 5%
Maryland and Virginia 4.8 4.2 -12%
Loftin's suicide rates
District of Columbia 11.3 11.3 - 1%
Maryland and Virginia 10.4 9.3 -11%Loftin suggests that DC's handgun ban saved 47 lives per year -- 3.3 gun-related homicides and 0.6 gun-related suicides per month. This view collapses when the per-capita rates are examined. Some lives were saved by the overall death rate decline visible in both groups, but the body count dropped mostly because many people moved out of the District of Columbia. Body counts in neighboring areas didn't drop, simply because the declining death rates were outpaced by a rapidly growing population.
According to my count, the District experienced a 3% better post-ban homicide rate reduction than did the neighboring communities. This is the only portion of the reduced homicide rate that could be attributed to DC's more restrictive handgun control, and amounts to about 6 lives per year. This is too small to be statistically significant.
According to Loftin's numbers, adjusted to a per-capita basis, the District's post-ban benefit vanishes altogether. Its proportionate rate reductions are smaller than those achieved by its neighbors.
It may still be true that the fractions of homicides and suicides related to guns were reduced. This must not be mistaken for a reduction in the actual homicide and suicide rates. Concerning suicide in particular, Loftin's suggestion that this example supports the Zimring- Cook weapons-choice theory over the substitution observed by Sloan- Rivara is directly contrary to the data.
Loftin's report dismisses a number of confounding factors, but fails to present adequate justification for doing so. Despite claims to the contrary, the presented measure of lives saved by the District's restrictive handgun policy is structured such that it is inherently contaminated by:
- lives saved by a region-wide drop in homicide and suicide rates
from other causes, affecting both study areas;
- lives saved by the population exodus from the District;
- killings in which non-firearms means were substituted for firearms.My analysis suggests that essentially all of the benefit perceived by Loftin is the result of this or similar contamination.
Finally, the study period ends in 1987, just as Washington DC began suffering a continuing homicide wave that earned it the dishonor of being the Murder Capital of the United States. It is doubtful that many opponents of restrictive handgun controls will be swayed when a city experiencing a doubling of its already horrendous homicide rate is simultaneously heralded as a successful example of such controls.
Dean Payne
deanp@lsid.hp.com
Washington DC area populations (in thousands) and homicides (murders and
nonnegligent manslaughters).
DC-MSA DC-city MD/VA
Year homicides pop homicides pop homicides pop
----------------------------------------------------
1960 139 2002 k 81 765 k 58 1237 k
1961 131 2002 88 43
1962 127 2111 91 36
1963 133 2220 95 38
1964 193 2300 132 61
1965 197 2392 148 49
1966 190 2481 141 49
1967 230 2685 178 791 52 1894
1968 262 2755 195 778 67 1977
1969 349 2799 287 762 62 2037
1970 326 2861 221 756 105 2105
1971 357 2907 275 758 82 2149
1972 367 2953 245 752 122 2201
1973 399 3029 268 734 131 2295
1974 408 3039 277 721 131 2318
1975 365 3030 235 710 130 2320
1976 309 3071 188 696 121 2375
1977 313 3043 192 683 121 2360
1978 295 3036 189 670 106 2366
1979 281 3011 180 656 101 2355
1980 326 3042 200 635 126 2407
1981 350 3085 223 636 127 2449
1982 334 3095 194 631 140 2464
1983 298 3305 183 623 115 2682
1984 285 3391 175 623 110 2768
1985 243 3464 147 626 96 2838
1986 298 3507 194 626 104 2881
1987 367 3612 225 622 142 2990
1988 547 3705 369 620 178 3085
1989 640 3767 434 604 206 3163
1990 684 3924 472 607 212 3317
1991 719 3968 482 598 237 3370
1992 677 4307 443 589 234 3718
1993 467
Averages
1968-76 349.1 2938.2 243.4 740.8 105.7 2197.4
1977-87 308.2 3235.5 191.1 639.2 117.1 2596.4
1988-92 653.4 3934.2 440.0 603.6 213.4 3330.6
Homicides per 100k population
1968-76 11.9 - 32.9 - 4.81 -
1977-87 9.5 - 29.9 - 4.51 -
1988-92 16.6 - 72.9 - 6.41 -
========================== Notes =====================================For Loftin's study, 'before' is Jan 1968 to Sep 1976, 'after' is Oct 1976 to Dec 1987. Because my data is annual, not monthly, I counted all of 1976 as 'before'. This ought not be significant, especially in light of the legal battles that suspended the ban from Dec 1976 to Feb 1977.
The Washington D.C. - Maryland - Virginia Metropolitan Statistical Area (DC-MSA) consists of the District of Columbia, Calvert, Charles, Frederick, Montgomery and Prince Georges Counties, MD, Alexandria, Fairfax, Falls Church, Manassas and Manassas Park Cities, and Arlington, Fairfax, Loudoun, Prince William and Stafford Counties, VA. Homicides and populations are taken from the annual FBI Uniform Crime Reports (UCR) - Appendix IV of recent editions, Table 4 or 5 of earlier editions.
District of Columbia (DC-city) homicides, and populations since 1979, are also taken from the UCR. Earlier populations are taken from the Census Bureau's 'Statistical Abstracts of the U.S.' Different editions of the Statistical Abstracts give differing populations for any given year.
Figures for the neighboring Maryland and Virginia (MD/VA) community are derived by subtracting the DC-city figures from the DC-MSA figures.
Homicides listed here are murders and nonnegligent manslaughters as listed in the UCR. Manslaughters by negligence, not listed since 1976, are excluded.
The New England Journal of Medicine. 1991 Dec 5. 325 (23). pp 1615-1620.
Special Article: Effects Of Restrictive Licensing Of Handguns On Homicide And Suicide In The District Of Columbia.
Loftin-Colin, McDowall-David, Wiersema-Brian, Cottey-Talbert-J.From the Violence Research Group, Institute of Criminal Justice and Criminology, University of Maryland at College Park, 2220 Lefrak Hall, College Park, MD 20742-8235, where reprint requests should be addressed to Dr. Loftin.
ABSTRACT:
Abstract Background. Whether restricting access to handguns will reduce firearm-related homicides and suicides is currently a matter of intense debate. In 1976 the District of Columbia adopted a law that banned the purchase, sale, transfer, or possession of handguns by civilians. We evaluated the effect of implementing this law on the frequency of homicides and suicides. Methods. Homicides and suicides committed from 1968 through 1987 were classified according to place of occurrence (within the District of Columbia or in adjacent metropolitan areas where the law did not apply), cause (homicide or suicide), mechanism of death (firearms or other means), and time of occurrence (before or after the implementation of the law). The number of suicides and homicides was calculated for each month during the study period, and differences between the mean monthly totals before and after the law went into effect were estimated. Results. In Washington, D.C., the adoption of the gun-licensing law coincided with an abrupt decline in homicides by firearms (a reduction of 3.3 per month, or 25 percent) and suicides by firearms (reduction, 0.6 per month, or 23 percent). No similar reductions were observed in the number of homicides or suicides committed by other means, nor were there similar reductions in the adjacent metropolitan areas in Maryland and Virginia. There were also no increases in homicides or suicides by other methods, as would be expected if equally lethal means were substituted for handguns. Conclusions. Restrictive licensing of handguns was associated with a prompt decline in homicides and suicides by firearms in the District of Columbia. No such decline was observed for homicides or suicides in which guns were not used, and no decline was seen in adjacent metropolitan areas where restrictive licensing did not apply. Our data suggest that restrictions on access to guns in the District of Columbia prevented an average of 47 deaths each year after the law was implemented. (N Engl J Med 1991;325:1615-20.).
TYPE OF FATALITY BEFORE THE
AND LOCATION LAW CHANGE AFTER THE LAW* T-STATISTIC
no./mo. no./mo. SE %
Homicide
District of Columbia
Gun-related 13.0 -3.3 0.49 -25 -6.73
Non-gun-related 7.3 -0.3 0.36 -4 -0.83
Maryland and Virginia
Gun-related 5.8 -0.4 0.35 -7 -1.14
Non-gun-related 3.0 0.7 0.26 23 2.69
Suicide
District of Columbia
Gun-related 2.6 -0.6 0.20 -23 -3.00
Non-gun-related 4.4 -0.4 0.29 -9 -1.38
Maryland and Virginia
Gun-related 9.2 1.1 0.45 12 2.44
Non-gun-related 9.9 -0.2 0.49 -2 -0.41
*Difference between the mean number of fatalities per month before the
implementation of the gun-licensing law and the mean number after its
implementation.