StatsCan Defense In The Mark

My post on the MLI's critique of StatsCan Crime Stats is up in The Mark. Those who were not previously convinced by the arguments contained therein, shall now be convinced. Those of you in the publishing business will immediately think "Damn that's good! I need to see one of this guys' many, many, many unpublished novels." And you may, as they are all unpublished, as I say.

Elsewhere, the MLI study takes a few more nasty hits.

The Macdonald Laurier Institute On Canadian Crime

So, it is pretty clear that the Macdonald Laurier Institute (MLS), which put out this study criticizing Stats Canada's reporting of crime statistics, has close connections with the current federal government, whose ideological views the study seems to reinforce. I don't want to make too much of that, because its hard to argue against some of their more generic methodological recommendations: Stats Canada should report more fully and completely and in a more open fashion. So should every body that produces statistical information. But life is tough, and times are hard, and money is short.

So I am only going to touch on a couple of issues mentioned in the study (which, I am proud to say, I have actually read from end to end). Here's the first one:

The annual report on crime statistics, know as Juristat, routinely revises crime statistics from previous years upward in any given year’s report, making annual crime decreases appear more significant than they are.

OK. Below is the relevant time-series from the Juristat report in question. It displays the ebbs and flows in Canada's Crime Severity Index (note: a chart showing the more traditional measure of crime by volume can be found here. There is no accompanying graph, but it would look generally similar to the one below):
What the analysts from MLI are saying is that, when Stats Can reports the data point for 2009, it will be measured against a point on the graph representing 2008 that has been upwardly revised. Thus any decline year-over-year will be accented, and any increase muted. That's not surprising: an initial StatsCan crime report is issued, more data comes in that was not available at the publication date, and the report and accompanying graph is updated. It isn't as though there is anything that could be done to get around this this, other than making publication date so late that revisions are unnecessary.

But, more importantly, the issue MLI identifies only really applies to the last couple of data points on the X-axis of the graph above. Stats Canada figures might be revised once or twice, but eventually they become pretty much set in stone, so the revisions MLI notes will not alter the overall shape of the graph. Which is to say, the revisions will not show a long-term downward trend if there is an upward trend in the underlying crime data. The downward trend in crime that Stats Canada notes really is there.

There's one other point in the MLI study that I would like to touch on, because it seems representative of a number of the criticisms that they make:

This is, as the MLI admits, a methodological complaint. Stats Canada chops up and recombines its numbers based on a series of methodological decisions. But these are not the only decisions that could have been made, and indeed when you make re-cut the numbers as per MLI, you get table 7 above. The question then becomes whether this, as MLI asserts, is a "much better" way of chopping up and recombining the numbers or not, and whether the result is worthy of highlighting in the Stats Canada report, or not.

I will not defend the agencies various methodological decisions in this space, for they have already done on their own behalf, here.

On Mongering In Fear

From an unsigned piece in The Interim:

A pro-life stance requires a willingness to make sacrifices to create a home for a stranger. Making a place for an unexpected child can involve huge changes in one’s life. The willingness to do so is choked off by an attitude which says that your only concern should be your own welfare and safety, that since no one is looking out for you, you had better look out for yourself.

Powerful forces are aligned behind the fear-mongering Media outlets, security companies, various politicians and police forces stand to benefit by the public being convinced that crime is out of control. The fear created has implications which extend far beyond the issue of crime. We need to think and discuss as a society what all those implications are. The evils which such fear breeds will in the end be far greater than any crime problem we presently have. The victims, I believe, will include the unborn.

Stockwell Day On Unreported Crime Stats

As Kady suggests, Stock must have been referencing the 2004 National Victimization Survey, part of the General Social Survey, which is conducted every five years, when he argued this morning that Canada had seen an "alarming" increase in "unreported crime". Forget that the latest report dates from 2004 and tells you nothing about what's happened since. Here's what it says in one of the fact sheets for the General Social Survey. They're referring to "violent crimes":

Police reporting rates remain stable

Rates of reporting violent incidents to the police remained stable between 1999 and 2004. In 1999, 31% of violent incidents were reported to the police, compared with 33% of incidents in 2004. This difference was not statistically significant.

Mind you, when it comes to overall reporting, Stock isn't entirely off his nut:

The GSS reveals that a large proportion of Canadians never reported criminal incidents to police. In all, only about 34% of criminal incidents came to the attention of police in 2004, down from 37% in 1999. Household victimization incidents were most likely to be reported (37%), while thefts of personal property were the least likely (31%).

I'll leave it to the reader to decide whether or not a three per cent drop in reported criminal incidents is "alarming".

Lorrie Goldstein: Things Were Better Long Ago

In which Lorrie Goldstein opines the Good Old Days, and suggests that Stats Can statisticians are the same variety of Commie as Climate Scientists.

Jesus. People were whining about the good old days back in the good old days when I was young.