I’m curious about something. How do we know about how much illegal activity takes place? How do we know the prevalence of illegal drug use? How do we know how much contraband of all kinds is brought into the country illegally? Or the number of people who’ve entered the country illegally? Or the crime rate among illegal immigrants?
In Chicago the “resolution rate”, the rate at which an arrest is made and a case goes to court, for homicides is around 15%. In other words we have no real idea of who the murderer was in 5 out of 6 cases. It is assumed they were gang-related because of the nature of the victims but we don’t really know.
Would there be policy implications if the numbers we’re assuming were twice what we’ve assumed they are? Or half? I would like to think so. That’s why I was so interested, for example, in “sewage epidemiology”. That’s an attempt at arriving at an empirical measurement of something that’s very hard to measure directly. I think we should be devising more such strategies. Models, interpolation, and extrapolation aren’t nearly enough.
We’re not the only ones who have this problem. I think that every large country has it. In China the people’s behavior frequently does not comport with what the official statistics say. People behave as though prices were rising out of control when the official statistics say they’re rising very slowly. Who do you believe?
It is widely believed that the data on violent crime is probably OK, especially homicides since they are hard to hide. The other crime is hard to be sure about. Pretty nifty study I would say.
Steve
With drug use, we wouldn’t know about the casual users who don’t end up in the statistics. That seems to be about it. What’s the policy for people who use cocaine or ecstasy once or twice a year?