Heather MacDonald got into a dispute last week with Wesley Lowery of the Washington Post for a National Review article arguing that gentrification, and the displacement of the young black men who commit and are the victims of a disproportionate component of violent crime, was responsible for New York City’s continued drop in violent crime over the last few years, in spite of the “Ferguson Effect” rebound in crime from 2014 to 2016 in other major cities.
The Census’s Current Population Survey has tracked information for people in the New York City metropolitan area since 1979. Over most of this period, as MacDonald suggests, the percent of city residents who were young black men steadily declined:
The Census changed how it computed race in the mid-2000s, encouraging respondents to indicate more than one race and treating Hispanic ethnicity separately from race. Since many New Yorkers are Hispanics who identify as black (for example, Manny Ramirez, the Afro-Dominican baseball player, grew up in New York), the post-2004 values aren’t strictly comparable, but it appears that the trend reversed, and that there are more young black men than previously:
These population flows do not appear to be particularly responsive to the real wages of young black men, which declined steadily from 1979 through the mid-90s (during a period of generally rising violence in the city), rebounded temporarily during the late 90s boom, and have stayed fairly constant since then:
The most recent wave of gentrification appears to have in fact displaced more black women than black men (who were previously far outnumbered in New York City by black women). As a result, the ratio of young black women to young black men in New York has steadily declined for the last 25 years, after reaching a high at the same time as the city was at its most violent in the late 80s and early 90s:
Putting the total number of murders in the year on the y-axis, there is a pretty clear association (due admittedly largely to the time trend):
In part, the excess number of women was a direct result of crime- young black men were more likely to be imprisoned or killed in New York in the 90s than today. Young black women have left the city for greener pastures in Atlanta or Houston subsequently not merely because of gentrification but also because there were so few eligible black men around in New York. But it’s not impossible that the arrow of causality- from violence to elevated female:male sex ratios- goes in both directions. At least some meta-analyses of the relationship between violence and sex ratios across cultures suggest that an excess of women is as or more conducive to elevated violence as an excess of men.