I would, and Alexi may as well.
Yes, as we've said, there are some studies that claim that there's a relationship. Most of the literature that says this is in fact done by economists, not by criminologists.
The primary study, for instance, that one should be talking about is one of those cases in which the study was produced that showed data on every other year rather than every year, and on the basis of that concluded that there was a sharp and immediate decline in crime in California immediately after severe punishments were introduced for certain crimes.
What Canadian researchers Tony Doob--who will be here next week, and answer this question far better than I--and Cheryl Webster did was re-create the data and found that when you inserted the missing years the decline in the crime rate started well before the introduction of the legislation.
The problem we have is that there's been, from a statistical point of view, a long and sustained decrease in crime throughout North America, indeed around the world, for the last 20 years, and during that period of time everybody who's done anything claims that what they did is responsible. So we have endless, usually small studies by given states or jurisdictions, or claims by politicians who brought in a particular bill that they brought in this bill and now we're seeing this decline.
The only way to really understand the phenomenon is to understand it in the context of the overall decreasing crime rates that have taken place over the last ten years. And when you do that, you find almost inevitably that the declines people are claiming their bill was responsible for in fact were preceded by declines that were already in place.