Deltoid

Greg Booth said:

A previous poster claims guns are not affective in stopping rapes. The evidence suggests otherwise.

[There was a gun training course for Orlando women in 1966]

The results?

In 1966 there were 36 rapes per 100,000 people in Orlando, triple the 1965 rate. In 1967, there were 4. Before the training, rape rates had been increasing in Orlando as nationwide. 5 years after the training, rape was still below pre-training levels in Orlando, but up 308% in the surrounding areas, 96% for Florida overall, and 64% nationally.

Cute. The rates for the period 1958-1972 can be found in Kleck & Bordua [1]. Their most notable feature is the extreme variation from year to year. By picking the right two years to compare you can get any result you want. For example, if I wanted to play the game, I would say:

"Since the training program started in 66 and ended in 67, we should compare 65 (last complete pre-training year) with 68 (first complete post-training year). Results? Three less rapes. In the whole period 61-72 the year with the closest rate to 65 is 68. In any case, the rate in 69 was 25% higher than in 65."

To do an honest comparison we need to do look at more than one year.

           58-66  67-72
Orlando    15.5   19.1
Surrounds  12.2   23.9

The rate did not increase by as much as in the surrounding area, but this is not good evidence for a long term benefit.

What about a short term benefit? Kleck [1] admits that the rate was extremely variable, but claims that because the change exceeded two standard deviations, random variation was insufficient to explain the change. However, in 64 there was a change almost as large and also exceeding two standard deviations.

Kleck also states that the percentage decrease was larger than in any other US city with a population of over 100,000. Kleck neglects to tell us what the population of Orlando was, but by looking at the granularity of the data you can deduce that the population of Orlando was less than 100,000 for the whole period 1958-1972. Comparing apples with oranges. Cute, real cute. Orlando itself experienced a larger percentage decrease in 1963.

To summarize, the variability in the data is sufficient to explain the change, without even considering other possible causes such as changes in the reporting rate or police procedures.

Also in 1967, violent assault and burglary decreased by 25% in Orlando, in addition to the rape reductions.

And homicide increased by 22%, in spite of decreasing in Florida overall. Should we chalk that up to the gun training program too?

The data in Kleck [2] let us roughly estimate the percentage of rapes where guns were used in self-defence. Guns were used for defence in about 1% of robberies (page 8). In Miami, guns were used to defend against robbery 19 times as often as against rape (page 10). In Florida, robbery is 8 times as common as rape [1,page 286]. This implies that guns were used in self defence in about 0.5% of rapes. Even 100% effectiveness of guns implies only a 0.5% decrease in the rape rate.

[1] Law & Policy Quarterly 5 pp 271-298 [2] Social Problems 35:1 pp 1-21