Because if you take proper care of children growing up, they are far less likely to commit crimes later in life. (More details and numbers at the link)

Economists love to say “there is no such thing as a free lunch”. We often use it to describe the opportunity cost of scarce resources, but it is also literally true, and therefore hunger and poverty are usually positively correlated. This is because without income and work, there can be no trips to the grocer. And without ingredients, there can be no meals. And without regular meals, children eke out a level of consumption so small, they grow up malnourished and live below the biological minimum level needed for child development. Poverty, through malnourishment and stunted child development, can can make life feel hopeless, and hopelessness can make desperate choices appear best.

Andrew Barr and Alexander Smith have produced an exemplar study that plausibly shows that the Food Stamp program, by dramatically improving the development of cohorts through increased nutrition, caused a sizable decline in birth cohort crime at the onset of early adulthood. This paper adds to a growing body of research that shows early childhood interventions can have developmental ramifications so large, they may change a person’s entire life trajectory and in so doing, society itself.

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But a separate literature explored whether childhood environments might be responsible for changing crime in adulthood. In a famous study by John Donohue and Steven Levitt, abortion legalization was suggested as at least partly responsible for the large, secular declines in crime that began in the early 1990s. But this theory was questioned and has since been more or less dropped by social scientists as an explanation for shifts in American crime rates. More promising explanations have focused on lead exposure and removal. But very little work, save a couple of small RCTs, have suggested that nutrition might be responsible for adult crime.

That has changed recently, though, in the last few years. Jill Carr and Analisa Packham, in a series of papers, present evidence that SNAP benefits can impact adult crime and domestic violence, but their work has tended to emphasize the program’s scheduling characteristics, not in utero and childhood development itself. Barr and Smith are unique in this pantheon of crime papers because of their focus on the Food Stamp Program’s nutritional benefits as opposed to the rational calculation of crime itself by adults. By providing nourishment and alleviating the sharp negative effects of poverty on the body’s development which can increase broadly defined human capital stock, something like a Food Stamp Program might reduce adult crime, not by changing the incentives adults face, but rather by changing the adult altogether.

This along with evidence of the effects of lead exposure, particularly through tetraethyl lead in gasoline, have had long term effects on crime rates. (See here, here, and here)

Spending money on policing, rather than treating making sure that children grow up with proper nutrition, healthcare and education is more than a cruelty, it is a stupidity.