The theme of Melissa Kearney’s book is in the title. To summarise, she argues that the decline in marriage rates in the United States since the 1980s has led to an increase in the number of children living in one-parent families – the one parent in nearly all cases being the mother. Those childrens’ life chances have been impaired - their chances of having a degree or a high income are diminished - and they are more likely than average to become single parents themselves. Thus, a vicious circle of inequality has become established.

Kearney devotes a great deal of space to reassuring her readers that she isn’t mounting an attack on single parents, or asserting that all marriages should be preserved regardless of the circumstances. She is, she says, ‘an economist, not someone with a moral or value-laden proposition’. This reassurance may seem unnecessary, but it probably isn’t.

Kearney supports her argument with a vast mass of statistics; indeed much of the book consists of the setting-out and description of survey data. The evidence that she cites shows that the percentage of children in single parent homes rose substantially between 1980 and 2010, and that single mothers come have come increasingly and disproportionately from the least-educated group of women. The incidence of single parent families varies widely among ethnic groups: in 2019, only 38% of black children lived with married parents, whereas the percentages among Hispanic, white and Asian children were 62, 77 and 88 respectively.

The next stage in Kearney’s argument is to show that children fare better if raised by married couples than if by single parents. This she is able to demonstrate from statistics and studies of educational attainment and income: the ‘marriage premium’ accrues to children of mothers with all levels of education, not just to those whose mothers have only basic education.

The obvious question is why the incidence of marriage has fallen. Kearney is at her least convincing when addressing this question. She suggests that men have become less ‘marriageable’, that is, less attractive to women as potential husbands. This, she says, is because their incomes have fallen relative to womens’ (a by-product of the movement towards gender equality), and because of rising unemployment and imprisonment rates. However, unemployment among men has fallen in the USA since 1980, though the number of people in prison has more than trebled, to 1.9% of the adult male population.

Kearney, being an economist, looks for economic explanations of social phenomena. She cites a statistical correlation between incomes and marriage rates, and evidence that declines in incomes in particular places are followed by declines in marriage rates. But, as Kearney herself points out, surely correctly, fathers can make a positive difference to their childrens’ lives, even if they don’t earn much money. Women might therefore value their presence for other reasons than money. It therefore isn’t clear why a fall in men’s relative earnings should have led to such a large fall in marriage rates. It is interesting to note that the marriage rate in the USA throughout the period from 2003 – 2018 (the latest date for which I could find data) was lower than in 1932, at the worst of the Great Depression.

Kearney argues that non-economic phenomena have been influential in other social changes, specifically the fall in teenage pregnancies. In the case of the falling marriage rate, too, perhaps the explanation goes beyond the purely economic. It might be significant that the percentage of children living with married parents varies so much among ethnic groups, because it suggests that the reasons for the decline in marriage include some which are in some sense cultural or religious. It’s a pity that Kearney doesn’t explore this possibility further.

Kearney’s policy conclusions are in my judgment a bit tame and short of detail: the main ones are to improve in some unspecified way the economic position of men without a college education so that they become more reliable marriage partners, and to have a stronger safety net for families, regardless of their structure. These may be desirable policies, but in the absence of a more compelling explanation of the decline in marriage, they did not wholly convince this reader.

The subject of the book is both complicated and important, particularly in a country that prides itself on equality of opportunity. Regardless of what you think of her policy proposals, Kearney has performed a great service by setting out the facts succinctly and clearly. Her book is well written and always interesting.

She clearly believes that public policy in the United States should be driven by evidence rather than by ideology. In that she is surely right, and her work is likely to help make it happen.