Consider this genuinely interesting map of which cities have more single men than single women and vice versa. All other things being equal you’d expect a small surplus of single women practically everywhere—there are slightly more female babies born than male babies every year and more girls make it into adulthood than boys, especially now that death in childbirth has been reduced since its high water mark a century ago.
The map shows a tendency for cities to have more single women than men east of the Mississippi, more single men than single women west of the Mississippi, and that the larger the city the greater the imbalance with the exception of Chicago.
The rather obvious explanation for the imbalance west of the Mississippi is immigration, particularly illegal immigrants. There are a lot more illegal male immigrants than female and lots more single men than families. If you’re thinking that the huge immigration from Mexico to the United States has some pretty drastic social implications, you’d be right.
But why are there so many more single women relative to single men east of the Mississippi? Are social and economic conditions there more conducive to women remaining single than west of the Mississippi? I’m open to suggestions for an explanation.
Note, too, that this imbalance has political implications which, as the math textbooks put it, I’ll leave for the interested student.
On reflection I think that my explanation holds up pretty well for explaining both the imbalance in the West and why Chicago’s imbalance is so small compared to other major cities. Is anybody else offering anything more convincing?
I’ll add one refinement to the explanation: Florida’s general pattern of more single men than single women is nicely explained by immigration (particularly illegal immigration). Miami’s larger proportion of women is probably explainable by women’s greater life expectancy.