Understanding Why Crime Fell in the 1990s: Four Factors that Explain the Decline and Six that Do Not

Abstract

Crime dropped sharply and unexpectedly in the United States in the 1990s. I conclude that four factors collectively explain the entire drop in crime: increases in the number of police, increases in the size of the prison population, the waning of the crack epidemic, and the legalization of abortion in the 1970s. Other common explanations for declining crime appear far less important. The factors identified are much less successful in explaining fluctuations in crime in the preceding two decades. The real puzzle is not why crime fell in the 1990s, but rather, why crime did not begin falling earlier.

Volunteering to be taxed: Business improvement districts and the extra-governmental provision of public safety

“…Attributing all this spending to BIDs' reduction in violent crime, this comes to roughly $21,000 of BID spending per averted violent crime. Compared to Levitt's (2004) estimate of $20,000 to $86,000 of police spending per violent crime, BIDs are both more efficient and more targeted. This comparison aside, it is clear from the perspective of a property owner that an additional $3,000 of taxes is more preferably spent and controlled locally than watered down across the city.…”

“…44 Ideally, I would compare this with the LAPD's cost per crime averted. Unfortunately, the closest reliable figures are national averages that I cite in the introduction (Levitt 2004). For a sense of the magnitude of local police expenditure, the LAPD spends approximately $5,000 per committed crime.…”

Voter, What Message Will Motivate You To Verify Your Vote?

“…Even in countries that use the severest possible penalty, i.e. the death penalty, there is no evidence that it reduces crime [35], thus we do not expect it to be efficacious in a voting context. In verifiable voting, understanding is seen to trump rewards and penalties.…”

Series Foreword

“…As economics has increasingly embraced the use of natural and field experiments, economists have produced more robust findings on the causes of crime. One of the leaders in the creative use of plausibly exogenous variation to identify crime causation is Stephen Levitt, whose research (and emergence as a celebrity, thanks to his book Freakonomics) has done much to inspire subsequent cohorts of graduate students in economics (Ayres and Levitt 1998;Levitt, 1996Levitt, , 1997Levitt, , 2004Levitt, 2005 When it comes to empirical methods, the leading edge for economics and criminology has converged in recent years. "Experimental criminology" is thriving and cuts across disciplines.…”