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