In Chapter 7

7.1 Is the scale of the effect realistic?

Lott's response is completely inadequate. As shown elsewhere permit holders are much less, not more, likely to encounter violent criminals.

His argument here is not even internally consistent. In his last paragraph he argues that if permit holders face the same risk of being attacked as everyone else, only 0.65% of permit holders need to thwart an aggravated assault to account for the observed drop in the assault rate. But in the previous paragraph he stated that only 0.18of the population are victims of aggravated assault, so if permit holders face the same risk as everyone else, only 0.18% of them will even have a chance to thwart an aggravated assault. This is much less than 0.65%, so if permit holders face the same risk, it is not possible for 0.65% of them to thwart an aggravated assault.

The fact that permit holders are less likely to be crime victims makes this comparison even worse for Lott.

7.2 The importance of ``crime cycles''

Lott is correct that he controls for national crime cycles, but the state time trends do not control for cycles at the state level.

Lott claims that the reductions in crime begin right when the carry laws were passed and that it too much of a coincidence to expect a crime cycle to have peaked exactly when the law was passed. However, as shown elsewhere the fact that the declines in Lott's graphs begin at the time of the law is an artifact of the way the graphs were created--it is not easy for a decline to begin anywhere else in his graphs.

7.3 Did Lott assume that there was an immediate and constant effect from these laws and that the effect should be the same everywhere?

While it is true that Lott also included models where the effect increased with time, the model given greatest prominence in his paper is the one with an immediate and constant effect. The abstract of that paper [31] states:

If those states without right-to-carry concealed gun provisions had adopted them in 1992, county- and state-level data indicate that approximately 1,500 murders would have been avoided yearly. Similarly, we predict that rapes would have declined by over 4,000, robbery by over 11,000, and aggravated assaults by over 60,000.

These numbers are based on the constant-effect model, so it does not seem unreasonable for critics to concentrate on that model.

7.4 When were these concealed-handgun laws adopted in different states?

While there do seem to be some problems in classifying when Maine and Virginia passed their laws, showing that the results do not depend on Maine or Virginia is a satisfactory response.

7.5 Should robbery be the crime most affected by the adoption of the non-discretionary law

This is discussed in detail here.

7.6 Do concealed-handgun laws cause criminals to substitute property crime for rape?

Lott does not seem to have even understood the criticism. Webster wrote ``theft is the motive for only a small fraction of the violent crimes for which Lott and Mustard find shall-issue effects''. Lott responds that robberies made up 34% of violent crimes, missing Webster's point that in his main analysis (table 3 of the paper and the results reported in the abstract), Lott and Mustard did not find a statistically significant effect on robbery.

7.7 Comparing crime rates for two to three years before non-discretionary laws go into effect with crime rates for two to three years after the passage of such laws

This criticism is from a draft of Black and Nagin's paper [5] and does not appear in the final version. It does not seem necessary for Lott to reply.

7.8 The impact of including Florida in the sample

This is discussed in detail here.

7.9 The impact of including Maine in the sample

Lott shows that excluding Maine has very little effect. I suspect that the critic has confused Maine with Florida.

7.10 How much does the impact of these laws vary across states?

This is discussed in detail here.

7.11 Do the coefficient estimates for the demographic variables make sense?

This is discussed in detail here.

7.12 Can we compare counties with discretionary and non-discretionary concealed-handgun laws?

Lott is correct in noting that it is the change in the number of permits that matters. However, he has that data for only a few states, which does not show consistent effects, possibly because there is so little data.

7.13 Should changes in the arrest rate be accounted for when explaining changes in the crime rate?

Lott argues that he accounted for the fact the crime rate and the arrest rate mutually effect each other with a two stage least squares analysis (2SLS). He claims that the 2SLS estimates provide ``even stronger evidence that concealed handguns deter crime''. This claim is wrong. It is true that the crime reductions associated with the laws are larger in the 2SLS analysis, but they are so much larger (a 67% reduction in homicide and a 65% reduction in rape) that they suggest that the model is incorrect.

Fortunately for Lott, his second argument is a better one--excluding arrests from the analysis has little effect on the results.

7.14 Are the graphs in Lott's book misleading?

Webster writes ``What is not obvious to the casual observer of the graphs is that each data point represents an aggregate average for states that liberalized their gun-carrying laws, but the states that make up the average are not the same each year.'' Lott denies that the graphs are misleading, but the test for whether the graphs are misleading is whether people have been misled.and it is clear that Webster has been misled by Lott's graphs. The data points on the graphs do not represent averages for states that liberalized their laws. Rather, the points are not data points at all, but just show where the curve fitted through the data points goes.

More about the problems with Lott's graphs is here.

7.15 Should concealed-handgun laws have differential effects on the murder rates of youths and adults?

This is discussed in detail here.

7.16 Are changes in the characteristics of victims consistent with the theory?

Lott's counterargument is that the observed changes in victim characteristics is not statistically significant. However, if the observed decrease in murder was caused by the laws, you would expect a change in the characteristics of victims. Failure to observe such a change is evidence that the change in the homicide rate was not caused by the gun laws.

7.17 Do non-discretionary concealed-handgun laws only affect crimes that occur in public places?

Lott argues that concealed carry laws could cause an increase in gun ownership and hence deter crimes in homes and other private places. However, Lott himself noted (page 28) that a Texas poll suggests that 97% of first-time applicants for concealed-weapon permits already owned a handgun, that is, concealed carry laws do not significantly increase gun ownership.

7.18 Is it reasonable to make comparisons across states?

Lott argues that while this objection was plausible when only a few states had implemented the laws, now that there is data from many states, the objection is now longer plausible.

The problem here is that while there is now data from many states, there is not much data from those states that have only recently changed their laws, and the results are dominated by the few states that have had their laws for a long time. When more data becomes

7.19 Does Lott's discussion provide a ``theory'' linking concealed-handgun ownership to reductions in crime?

Lott writes ``The theory is obvious: A would-be criminal is deterred by the risk of being shot.'' However, as discussed earlier, the change in that risk caused by concealed-carry law is negligible.

Lott goes on to argue that he can link the laws to the crime reductions because:

7.20 What can we infer about causality?

The question at issue is the possibility that some other factor than the gun law caused the reduction in crime.

Lott does have a good point when he argues that it would be better if critics who argue that some other factor caused the reduction in crime would specify what that factor was, however, as Lott concedes, it remains possible that some unknown factor caused the crime changes. Lott's own analysis that found crime trends before the laws were passed demonstrates that there were factors operating that were not explained in his model.

Lott goes on to argue that the reductions were not caused by ``other factors'' because:

7.21 Concerns about the arrest rate due to missing observations

Lott devotes a whole page to criticism of of Black and Nagin [5] conducting their analysis using only counties with populations of more than 100,000, implying that they were searching for a subset of the data to show that the laws had no effect.

This is a very strange criticism, since Lott and Mustard did exactly the same the thing: Page 35 of [31]

We reran all the regressions in this section first by limiting the sample to those counties over 10,000, 100,000, and then 200,000 people. Consistent with the evidence reported in Table 7, the more the sample was limited to larger population counties the stronger and more statistically significant was the relationship between concealed handgun laws and the previously reported effects on crime.
That is, according to Lott and Mustard's original paper, Black and Nagin's analysis was biased towards finding a beneficial effect for the gun laws.

Lott then writes:

Despite ignoring all these observations, it is only when they also remove the data for Florida that they weaken my results for murder and rape.
This statement is false. Black and Nagin report that removing Florida makes the effects on murder and rape not statistically significant whether or not the analysis is restricted to large counties.

7.22 What can we learn about the deterrent effects of concealed handguns from this study?

Lott doesn't really address the criticism in his answer. The criticism is directed at something Lott writes at the end of the chapter--that even his critics are correct and the models misspecified, the gun laws have no effect.

As Zimring and Hawkins note, this is not correct. If the critics are correct and the models wrong, you cannot draw any conclusion about the effect of the gun laws on crime. It would be possible for the laws to cause an increase, a decrease or to have no effect.

7.23 Summarizing the concerns about the evidence that concealed-handgun laws deter crime.

Lott's answer is about the state of the academic debate. This answer is updated in section 9.16, so it will be dealt with there.

He also complains about ``the reluctance of gun-control advocates to release their data'', mentioning Kellermann's study (data available from the ICPSR, study 6898) and the Police Foundation study on gun ownership and use (data available from the ICPSR, study 6955). While Lott may have had trouble getting this data, it is publicly available on the Internet.

Tim Lambert