More Guns Less Crime by John Jr (ebook reader macos .txt) 📗

of the law indicates that crime was rising. The results using the simple time trends for these violent-crime categories are reported in table 4.8. Figures 4.5 through 4.9 illustrate how the violent-crime rate varies before and after the implementation of nondiscretionary concealed-handgun laws when both the linear and squared time trends are employed. Comparing the slopes of the crime trends before and after the enactment of the laws shows that the trends become more negative to a degree that is statistically significant after the laws were passed. 36

These results answer another possible objection: whether the findings are simply a result of so-called crime cycles. Crime rates rise or fall over

Table 4.6 Results of rerunning the regressions on differences

Endogenous variables in terms of first differences of the natural logarithm of the crime rate

Exogenous variables

Aln(violent-Aln(Murder Aln(Rape Aln(Aggravated-crime rate) rate) rate) assault rate)

Aln(robbery Aln(property- Aln(Burglary Aln(Larceny Aln(Auto-rate) crime rate) rate) rate) theft rate)

All variables except for the nondiscretionary dummy differenced

Nondiscretionary law adopted

First differences in the arrest rate for the crime category

First differences in the dummy for nondiscretionary law adopted

First differences in the arrest rate for the crime category

-22%*

-0.05%*

-2.6%

-0.15%*

-5.2%* -4.6%*

-0.09%*

-0.09%*

-3.3%*

-0.06%*

5.2%*

-0.0

3.5%*

-0.24%*

All variables differenced

-2.7%*

-0.05%*

-3.6%*

-0.15%*

-3.9%*

-5.4%*

-0.09%*-0.09%*

-0.7%

-0.06%*

-0.0

0.7%

-.24%*

5.2%*

-0.02%*

6.2%*

-0.02%*

12.8%*

-0.02%*

24.2%*

-0.02%*

Note: The variables for income; population; race, sex, and age of the population; and density are all in terms of first differences. While not all the coefficient estimates are reported, all the control

variables used in Table 4.1 are used here, including year and county dummies. All regressions use weighted least squares, where the weighting is each county's population. Entire sample used over

the 1977 to 1992 period.

*The result is statistically significant at the 1 percent level for a two-tailed t-test.

***The result is statistically significant at the 10 percent level for a two-tailed t-test.

****The result is statistically significant at the 11 percent level for a two-tailed t-test.

CONCEALED-HANDGUN LAWS ANDCRIME RATES/75

Table 4.7 Permits granted by state: Florida, Oregon, and Pennsylvania

"Estimate of the number of concealed-handgun permits issued immediately before Florida's law

went into effect from David McDowall, Colin Loftin, and Brian Wiersema, "Easing Concealed

Firearms Laws: Effects on Homicide in Three States," Journal of Criminal Law and Criminology, 86 (Fall

1995): 194.

December 31, 1991.

'Number of permits issued under discretionary law.

time. If concealed-handgun laws were adopted at the peaks of these cycles (say, because concern over crime is great), the ensuing decline in crime might have occurred anyway without any help from the new laws. To deal with this, I controlled not only for national crime patterns but also for individual county patterns by employing burglary or robbery rates to explain the movement in the other crime rates. I even tried to control for individual state trends. Yet the simplest way of concisely illustrating that my results are not merely a product of the "normal" ups and downs in crime rates is to look again at the graphs in figures 4.5—4.9. With the exception of aggravated assault, the drops not only begin right when the laws pass but also take the crime rates well below what they had been before the passage of the laws. It is difficult to believe that, on the average, state legislatures could have timed the passage of these laws so accurately as to coincide with the peaks of crime waves; nor can the resulting declines be explained simply as reversions to normal levels.

Was the Impact of Nondiscretionary Concealed-Handgun Laws the Same Everywhere?

Just as we found that the impact of nondiscretionary laws changed over time, we expect to find differences across states. The reason is the same in both cases: deterrence increases with the number of permits. While the information obtained from state government officials only pertained to why permits were issued at different rates across counties within a

Toble 4.8 Chonge in time trends for crime rotes before ond after the adoption of nondiscretionory lows

Percent change in various crime rates for change in explanatory variable

Violent Aggravated

crime Murder Rape assault

Property Robbery crime Auto theft Burglary Larceny

Change in the crime rate from the difference in the annual change in crime rates in the years before and after the change in the law (annual rate after the law — annual rate before the law)

-0.9%*

-356*

-1.456* -0.5%*

-2.7%*

-0.6%*

-0.3%*

-1.5%*

-0.1%

Note: The control variables are the same as those used in table 4.1, including year and county dummies, though they are not reported, because the coefficient estimates are

very similar to those reported earlier. All regressions use weighted least squares, where the weighting is each county's population. Entire sample used over the 1977 to 1992

period.

*The result is statistically significant at the 1 percent level for a two-tailed t-test.

**The result is statistically significant at the 5 percent level for a two-tailed t-test.

-4-2024

Years before and after the adoption

of concealed-handgun laws

Figure 4.5. The effect of concealed-handgun laws on violent crimes

-6-4-2 0 2 4

Years before and after the adoption of concealed-handgun laws

Figure 4.6. The effect of concealed-handgun laws on murders

3 Q. O

Q.

E

-10

10

Years before and after the adoption of concealed-handgun laws

Figure 4.7. The effect of concealed-handgun laws on rapes

a o

Q.

.Q 9

E

-10

10

Years before and after the adoption of concealed-handgun laws

Figure 4.8. The effect of concealed-handgun laws on robbery rates

CONCEALED-HANDGUNLAWS ANDCRIME RATES/79

Years before and after the adoption of concealed-handgun laws

Figure 4.9. The effect of concealed-handgun laws on aggravated assaults

given state, the rate at which new permits are issued at the state