Freakonomics | Study Guide

Steven D. Levitt & Stephen J. Dubner

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Freakonomics | Chapter 4 : Where Have All the Criminals Gone? | Summary


Key Takeaways

Since conventional wisdom often links cause and effect through proximity and distance, the example of the link between abortion and low crime rates 20 years apart shows how difficult it can be for the brain to make these kinds of connections without evidence. The authors aim to show how the causes of some effects are much more distant than one might expect.

  • To strengthen the country by incentivizing population growth, dictator Nicolae Ceauşescu of Romania declared abortion illegal in 1966.
  • The incentive worked, and within one year the Romanian birth rate doubled.
  • Compared with children born within the last few years during the time when abortion was legal, the lives of these new children was much worse: they performed worse in school, were less likely to find work, and were more likely to become criminals.
  • Ceauşescu was overthrown 20 years later by young people who might not have existed were it not for his abortion ban.
  • In ways, this story is the dramatic opposite of the American crime story of the 1990s when crime dropped precipitously as a consequence of the 1973 law legalizing abortion.
  • At a loss to explain the sudden decline, experts attributed it to a better economy, "increased reliance on prisons," increased police forces, and gun control—none of which are supported by the data.
  • Innovations in policing offered the most attractive theory for the crime reduction, largely because it appealed to conventional wisdom, but in New York City, which enjoyed the highest drop in violent crime, policing innovations weren't implemented until well after the decline had begun.
  • By 1980 the number of abortions reached 1.6 million per year, which translates into 1.6 million American women a year who became pregnant and did not have a child.
  • Women most likely to have an abortion were likely unmarried, teenagers, or poor.
  • Two of the biggest indicators of whether a child will grow up to become a criminal are
    • growing up in poverty and with a single parent.
    • growing up with a teenaged or uneducated mother.
  • The most dramatic effect of legalized abortion emerged in the early 1990s—when crime dropped dramatically—precisely when the majority of babies born after the Roe. v. Wade decision were entering their teens.
  • Because children most likely to become criminals had not been born, legalized abortion resulted in less crime.
  • Although this is a highly controversial theory, people tend to believe events result from immediate and tangible causes rather than distant and nuanced ones—it's easier to believe theories about gun control and effective policing because they are "near-term" causes.
  • Testing for causality rather than correlation means measuring crime data in the five states where abortion was legal before the Supreme Court decision made it legal for the entire country.
  • Examining the data for those states shows crime began to fall earlier than in the other states where abortion was still illegal.
  • Examining the correlation between each state's abortion rate and crime rate also shows the states with the highest abortion rates in the 1970s experienced the greatest crime drops in the 1990s, proportional to states with low abortion rates and smaller drops in crime.
  • The states with the highest abortion rates in the 1970s experienced the largest reductions in crime in the 1990s. These data mirror how states with lower abortion rates had a proportionally lower drop in crime.
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