Crime researchers pump out studies almost daily, it seems, with implications for the policy choices we must make. At bottom, though, a study can be no better than the data that go into it. As they say in the computer industry, "garbage in, garbage out." Numbers can be run through sophisticated statistics software, and the results can be dressed up with snazzy graphics, but if the raw data are bogus, the graphs are meaningless at best and dangerous at worst.

In the New York Post, Philip Messing, Larry Celona, and James Fanelli have this disturbing story about cooking the books on crime stats as a result of the data-driven police management system, CompStat.