Yes, it is amazing how America is in such better shape now than it was in 1990.
Gradual recovery from the corrosive legacy of Ronald Reagan.
I think crime went down because of the internet.
Before the internet kids had nothing to do but have sex and get high all day. The internet took all that negative energy and channeled it into something more productive, like making videos of your cat or of your best friend getting kicked in the balls.
I imagine the pre-internet days were like the movie Slacker or Stranger than Paradise. Both movies are about how boredom breeds all sorts of strange behavior. Now we’re less bored, and less likely to behave strangely.
There is of course the famous argument by Levitt/Donahue that legalization of abortion in the early 70’s contributed to falling crime rates in the 1990’s. There has been a debate about the paper but their argument and evidence still looks pretty convincing.
Or we’ll behave strangely, but we’ll do it online. 
Abortion went up sharply after Roe v Wade. The argument is that the fetuses that were aborted would have taken ~15 - 20 years to become criminals, thus the corresponding decrease in crime rates is time-lagged about that many years after the increased availability of abortion.
You could make a similar argument about the sharp decrease in abortion in the 90s. The higher abortion rate after '73 and through the 80s removed people from the population ~15 - 20 years in the future who would have otherwise been a sub-population with a very high abortion rate.
See here - the start of the precipitous drop in the abortion rate occurs around 1992. 19 years after Roe v Wade.
This post seems familiar, somehow, but I just can’t figure out why.
An aging population will tend to make all those things go down.
Could be. Here’s US birthrats by year. They drop pretty quickly in the mid-60’s on (I presume due to the pills introduction in 1960), but the drop in birthrates doesn’t really scale with the drop in crime twenty years later, when the effect of fewer crime-prone youngsters would presumably be felt. The birthrate drops 10% or less, while the violent crime rate went down about a third.
Still, the effect doesn’t have to be linear. As with the abortion argument, it may be that young people who weren’t born during the late sixties and early 70’s due to the acceptance of contraceptives were also the ones most likely to have been heisting banks twenty years on.
Well, happily, with the current assault on funding for Planned Parenthood, cutbacks for police budgets (so that they are laying off cops in Oakland and some departments starting to rely on volunteers), we should find ourselves back to the go-go '80’s in no time!
On an unrelated note, the above was my first use of an inline link on this board!
No big mystery (about the crime rate). Young males in the 15-30 year old age group) account for most violent crime.
When their numbers decline, the crime rate drops.
The corellation with unemployed young males is even stronger-you do not want to live in an area with high youth unemployment.
Except see my last post, the decline in crime rate has been a lot larger then the decline in young people.
Perhaps is that why crime rates increased in the 1960s-the draft ended and thus the poorer youths turned to stealing from local stores rather than fighting Vietcong troops?
The draft didn’t end till the early 70’s
Hm. One of the rare situations where a high crime rate is actually better for society than the alternative.