Kleck's DGU numbers

Steve D. Fischer writes:

First of all, you exaggerate the importance of burglary. From
Question B (pg 185) we find that 37,3% of the crimes occurred IN
the home.

and 35.9% near the home.

In Question C, we find that 33,8% of the respondents thought
that a burglary was in progress. So burglary accounts for at most 1
in 3 defensive events.

It is the most common of the crimes listed.

Non-home incidents represent 2 out of 3 crimes.

You seem to be classifying "near defender's home" as a non-home incident...

What's a major difference between crimes committed in the home
versus crimes committed on the street?

Only 21% of the crimes occured in public places (commercial place,
parking lot, school or street).

The presence of witnesses
who are neither victims nor a party to the crime.

What, always? Wouldn't criminals at least sometimes wait till there
were no witnesses around?

It doesn't "cost"
the witness anything to report a crime - especially if it's anonymous.

Sure it does. Time. The NCVS finds that only 40% of violent crimes
are reported by the victims. Third parties will have even less reason
to be involved.

There is no way to tell what fraction of that 64.2% of reports came
from the participants involved or from other witnesses to the crime.

We can estimate an upper bound: 21% of crimes in public places times
50% of these with witnesses (generous upper bound) times 40% of the
witnesses reporting it to the police (really generous upper bound)
times 50% of the time defender finding out that the police knew about
it. That's at most 2% of the reports.

Kleck reckons that only 3% told the NCVS about the DGU. If they are
just as likely to tell the police as the NCVS (again a generous bound
--- they're actually quite a bit less likely), then 64-3 = 61% of
reports were occasions where the police found out about the DGU from a
third party. This is thirty times greater than the upper bound
obtained above.

I think the conclusion is inescapable: most of Kleck's respondents
were untruthful when they said that the police were aware of the
incident. It doesn't necessarily follow from this that the whole
incident was made up, but there is a pretty good chance.

Tags

More like this