The other day I mentioned some odd incentives at work in the U.S. criminal justice system. After a little more reading on the subject, I came across another instance that isn't exactly earth-shattering, but interesting nonetheless.

During the 1990s (all data here) in New York City, misdemeanor arrests increased by about 56 percent, thanks in large part to the "broken windows" style of policing. Over that same time, felony arrests only slowly declined by about 17 percent. However, felony indictments declined much, much more quickly, by about 46 percent. In other words, the "overcharges," or felony arrests that did not result in indictment and/or conviction, absolutely exploded.

This held true for all types of cases. The indictment rate for violent felony arrests declined from 35 to 24 percent. The indictment rate for felony drug arrests went from 57 percent to 40 percent. Why? One obvious answer is that actual reported felonies declined by 52 percent during this time, so fewer felonies were actually being committed. Drug dealers also moved underground—so it was a lot harder for police to engage in "buy and bust" sting operations, which result in high indictment rates (since the officer is both complainant and witness.) So while arrests stayed at roughly the same level, the quality of arrests declined quite rapidly.

Now the problem here is that officers had every incentive to maintain the rate of felony arrests. After all, a police station that isn't arresting as many people will quickly get accused of not doing anything. Even though it's not arresting as many people because, well, it did it's job well. Success is deadly. So they continue to make felony arrests, even though there are fewer felons, or the felons are harder to find.

This wouldn't seem like a big deal, but overcharging clogs up and drains resources from the justice system. The detainees in question go in jail for longer periods (and often can't pay the much higher bail). Already overworked prosecutors have to spend time reviewing these cases before reducing or dismissing them. The whole thing leaves everybody worse off. But a rather simple change in the incentive system here could fix the problem pretty quickly, it seems.