The goal of the analysis in the next three chapters is one important step short of what most observers would want to know about the causes of New York City’s crime decline. Ideally, when crime drops by four-fifths in a major city, the goal would be to find what caused the entire drop. But the timing of the crime decline in New York City makes a comprehensive explanation of the city’s total crime decline intractably difficult. The first ten years of New York’s decline happened during a dramatic nationwide drop in crime, a drop that is only partly explained by factors such as the changing age structure of the population, general prosperity, and increases in incarceration. This national trend—which lasted until 2000 and was slightly less than half the magnitude of New York City’s decline—is largely unexplained in its size and timing, which makes it highly unlikely that the same level of decline during the same years would be easier to explain in New York City.
The strategy that I adopt here is an attempt to explain the difference between New York and the general trend, to focus on the larger drops during the 1990s and the longer decline period in the city, and to link this distinctive New York drop to other facets of social and governmental life in the city that also were not common to the rest of the country. The search is for distinctive changes in the city that fit the timing and magnitude of the exceptional New York crime decline. Even the best result from this type of analysis will explain a 40% crime drop rather than the 80% entirety that was charted in Chapters 1 and 2. But this half-a-loaf approach will not bog down in attempting, yet again, to find causes for trends that have eluded explanations when national-level data were examined. How might observations in one city resolve these national level uncertainties? If that sort of breakthrough is implausible, the prudent course is to put the national pattern to one side and explore the distinctive 18-year city level decline and the factors that might explain this New York difference.
The three chapters in this part of the book are organized as an increasingly specific process of elimination of potential explanations of New York (p.50) City’s special success in crime reduction. Chapter 3 is a wide-ranging survey of population, social, and economic factors thought to influence crime trends, which shows that most of the usual predictors of crime risk didn’t change in New York in ways that would help to explain the additional crime decline. Chapter 4 then examines the two predominant theories of crime risk in the 1990s: the expansion of high-risk youth and the high rates of drug sales and use. These pessimistic indicators didn’t change much but also didn’t produce the criminogenic future that was expected. Chapter 5 examines the major changes in police force levels, organization, and tactics, which are the only plausible changes in New York City available to help explain the length and the extra size of the city’s crime decline.