Are working mothers helping to cut crime?
Working mothers with young children now spend more time on childcare than did mothers without jobs in the 1970s.
Tonight on Newsnight, Katie Razzall will ponder whether this rise in parental attention is one of the factors that helps to explain recent falls in crime. Perhaps time investment in young children is paying dividends when they get older by helping to keep them out of trouble.
The finding on working mothers' childcare time comes from analysis of so-called time-use surveys. Sociologists occasionally ask people to keep a diary recording how long they spend on various tasks. Then they can track how certain tasks and roles have changed. That's one way that we know parents are working harder at parenting. That includes fathers, who have increased their investment in children. But the rise in childcare by mothers has been much larger.
So where has the extra time for working mothers come from? Not from working less, but from cutting leisure. They reduced time watching TV and listening to the radio from 113 minutes a day on average to 81 minutes between 1974 and 2005. Time spent eating dropped from 59 minutes to 37 a day.
There are also some curious technology driven changes: none of the working mothers reported time spent repairing clothes since 1987. Food preparation was down by 10 minutes to 41 minutes. (Working mothers now marginally spend more time preparing food than eating).
As Katie will be exploring, an effect of this may be the fall in crime rates. But it's worth pondering other effects. It probably helps to explain the "Flynn effect"; the fact that each generation seems smarter than the last. We invest more in our young at a key time in their development.
But it will probably also have another effect: children develop faster from interacting with more educated people. If everyone doubles their time with their children, all children do better - but the children of better educated families will get a bigger advantage.
So it's self-evidently a good thing that parents are putting so much care into their children, and enormously gratifying that the results might even be visible in the crime statistics. But it will also have an unexpected effect for schools; a bigger gap to close between rich and poor kids.
Watch Katie Razzall's report on Newsnight on Wednesday 23 April at 22:30 BST on BBC Two.