Why Crime Fell in the 1990s: Unraveling America’s Greatest Criminal Justice Mystery

The dramatic decline in crime during the 1990s remains one of the most remarkable social phenomena in modern American history. Understanding why crime fell in the 1990s has become a cornerstone topic in criminology, economics, and public policy. This unprecedented drop challenged every expert prediction and transformed how we think about crime prevention.

The Magnitude of the Crime Decline

The scale of America’s crime reduction in the 1990s defied all expectations. Between 1991 and 2001, homicide rates plummeted by 43 percent, reaching their lowest levels in 35 years. The FBI’s violent crime index fell by 34 percent, while property crime dropped by 29 percent during the same period. This wasn’t a temporary blip—crime fell consistently year after year, with homicide rates declining in nine of the ten years during the 1990s.

What makes this decline even more extraordinary is that it caught the entire criminological establishment off guard. In 1995, prominent experts were predicting a massive crime wave. Professor James Alan Fox warned that “the next crime wave will get so bad that it will make 1995 look like the good old days”. Instead, juvenile homicide rates fell by more than 50 percent in the following six years.

The crime reduction wasn’t limited to specific regions or types of communities. From New York City’s 73.6 percent reduction in homicide to smaller cities experiencing 20-30 percent decreases, why crime fell in the 1990s became a universal American story. Every demographic group, geographic region, and crime category experienced substantial declines.

Four Key Factors Behind the 1990s Crime Decline – Percentage Contribution to Overall Crime Reduction

Four Factors That Actually Explain Why Crime Fell in the 1990s

University of Chicago economist Steven Levitt’s groundbreaking research identified four primary factors that account for virtually all of the observed crime decline. These findings revolutionized our understanding of why crime fell in the 1990s and debunked many popular explanations.

1. Increased Police Forces: The Foundation of Crime Reduction

The expansion of police forces played a crucial role in explaining why crime fell in the 1990s. The number of police officers increased by approximately 14 percent during the decade, adding 50,000-60,000 officers nationwide. Using elasticity estimates of crime with respect to police numbers, this expansion can account for roughly 5-6 percent of the overall crime reduction.

The investment proved cost-effective. With annual police expenditures of approximately $60 billion, the 14 percent increase cost about $8.4 billion annually. However, the crime reduction benefits were estimated at $20-25 billion, making police expansion economically attractive.

2. The Rising Prison Population: Incapacitation and Deterrence

Perhaps no factor was more significant in explaining why crime fell in the 1990s than the massive expansion of America’s prison system. The prison population more than doubled during the 1990s, with over half of this growth occurring in that single decade. By 2000, more than two million Americans were incarcerated—four times the number imprisoned in 1972.

This increase worked through two mechanisms: incapacitation (removing criminals from the streets) and deterrence (discouraging potential offenders). Research estimates suggest the prison expansion accounted for approximately 12 percent of the reduction in violent crime and homicide, and 8 percent of the property crime decline.

3. The Waning Crack Epidemic: Violence Reduction

The decline of crack cocaine markets provided another crucial piece of the puzzle for why crime fell in the 1990s. The crack epidemic had devastated urban communities throughout the 1980s, with homicide rates among young Black males tripling between 1985 and 1991. As crack markets stabilized and violence decreased, homicide rates began their dramatic descent.

The evidence is particularly stark when examining demographic patterns. Young Black males experienced a 48 percent decline in homicide rates from 1991 to 2001, compared to 30 percent for older Black males. This differential decline suggests crack’s recession explains approximately 6 percent of the overall homicide reduction, or about 15 percent of the total homicide decline.

4. Legalized Abortion: The Most Controversial Factor

The most contentious explanation for why crime fell in the 1990s involves the long-term effects of abortion legalization following Roe v. Wade in 1973. Economists John Donohue and Steven Levitt argued that increased access to abortion reduced the number of unwanted births, and these avoided births would have disproportionately involved children at higher risk for criminal behavior.

The evidence supporting this theory includes several compelling patterns: states that legalized abortion before 1973 experienced earlier crime declines, states with higher abortion rates saw greater crime reductions, and the timing aligned with cohorts born after legalization reaching peak crime ages. The research suggests legalized abortion accounts for approximately 10 percent of the crime reduction across all categories.

Six Popular Explanations That Don’t Explain Why Crime Fell in the 1990s

Media coverage and political discourse promoted numerous theories about why crime fell in the 1990s, but rigorous analysis reveals most played minimal roles:

Economic Growth: Despite the 1990s economic boom, the relationship between unemployment and crime is weak. The 2 percentage point decline in unemployment can explain only about 2 percent of property crime reduction and had no impact on violent crime.

Demographic Changes: While the aging population theoretically reduces crime, these effects were largely offset by increases in the Black population and the echo boom generation reaching peak crime ages.

Innovative Policing Strategies: New York City’s “broken windows” policing received enormous attention, but most of NYC’s crime advantage disappears when accounting for its 45 percent increase in police officers—three times the national average.

Gun Control Laws: The Brady Act and various gun control measures showed no measurable impact on crime trends. States affected by the Brady Act showed no different homicide patterns than states already meeting its requirements.

Concealed Weapons Laws: Research claiming crime reductions from “shall-issue” concealed carry laws has proven fragile under scrutiny, with benefits disappearing when datasets are extended.

Capital Punishment: Even generous estimates suggest the quadrupling of executions during the 1990s reduced homicides by less than 2 percent.

The International Context: Why Crime Fell in the 1990s Differently Elsewhere

America’s experience contrasts sharply with other developed nations, providing additional evidence for the four-factor explanation of why crime fell in the 1990s. European Union countries experienced much smaller crime reductions during the same period—homicide rates fell only 4 percent compared to America’s 28 percent decline.

This international comparison supports the causal role of the four identified factors. European countries had relatively small increases in police and prison populations, no crack epidemic, and lower abortion rates than the United States. The absence of these crime-reduction catalysts helps explain why Europe didn’t match America’s dramatic improvement.

Implications for Understanding Crime Policy

The research on why crime fell in the 1990s reveals how media explanations can mislead public policy. Of the eight most frequently cited newspaper explanations, only three proved genuinely important. Meanwhile, legalized abortion—accounting for the largest single factor—received no media mention during the period.

This disconnect between popular perception and empirical reality has profound implications for resource allocation. If policymakers believe ineffective strategies drove the 1990s success, they may waste billions on programs that don’t reduce crime.

Looking Forward: Lessons from Why Crime Fell in the 1990s

Understanding why crime fell in the 1990s provides valuable insights for future crime reduction efforts. Of the four key factors, only continued police growth and the ongoing effects of abortion legalization were expected to contribute to further crime reductions in the 2000s.

Prison populations had stabilized by 2000, limiting future incapacitation effects. Crack-related violence had reached a steady state. However, substantial portions of the criminally active population were still born before abortion legalization, suggesting continued gradual improvements as these cohorts aged out.

The research also highlighted potential future challenges, including the coming of age of children raised in crack-affected environments during the 1980s, even though direct physiological effects of prenatal crack exposure appear limited. You may find Economic Contributions to the Understanding of Crime here

Frequently Asked Questions

The story of why crime fell in the 1990s demonstrates how rigorous empirical analysis can reveal surprising truths about complex social phenomena, challenging conventional wisdom and informing more effective public policies.

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