Is Extra Maternity Leave Bad for Child Cognitive Development?
Back in March we wrote about a Norwegian study which showed that an increase in maternity leave led to lower high-school dropout rates for the children of those moms. But a new working paper about maternity leave in Canada (abstract here) highlights some possible negative effects of extra maternity — specifically on a child’s cognitive development at ages 4 and 5. At issue isn’t the extra time a mother spends with her child, but the timing of when she returns to work, and the abrupt change it causes.
Michael Baker of the University of Toronto and Kevin Milligan of The University of British Columbia focused their research on a Canadian law passed at the end of 2000 that extended maternity leave from 6 months to a full year. As a result, the timing of the return to work changed from an average of just under 6 months to nearly 9 months:
We find that the expansion of parental leave — and the resulting extra time mothers spent with their child in his/her first year of life—had no positive impact on indices of children’s cognitive and behavioral development; this despite the fact it had substantial impacts on the maternal care and non-licensed non-parental care children received in their first year, as well as how long they were breastfed. For our behavioral indices we can rule out all but very modest improvements. For our cognitive measures the estimated impact of the reform is small, negative and statistically significant for PPVT and Who Am I? This latter result highlights the relatively neglected issue of how changes in maternity leave laws affect the timing of the mothers’ return to work. Specifically, it is consistent with the hypothesis that some ages are better than others for abrupt changes in the parent-child relationship.
The Cost of Eating Organic Food; or: Will E. Coli Increase Our Appetite for Irradiated Food?
We’ve been preparing a Freakonomics Radio piece on the hidden or overlooked costs of eating organic food. (Hint: living creatures that might be deterred by pesticides might not be deterred without pesticides.) In the meantime, a massive example has arisen in Europe, where the recent deadly E. coli outbreak has been traced to organic bean sprouts grown in northern Germany. In his Wall Street Journal column, Rational Optimist Matt Ridley makes a fervent argument that such an outbreak needn’t have happened:
A technology that might have prevented contaminated produce from infecting thousands of Germans with E. coli was vetoed—by Germany—11 years ago for use in the European Union. Irradiating food with high-voltage electrons is a process that can kill bacteria on or in solid objects, just as pasteurization can kill them in liquid foods.
When the European Commission proposed in 2000 that irradiation be allowed for a greater range of foods and at a higher dose, the German government vetoed the measure. In the U.S., food irradiation is used for various products, including ground beef, but most retailers resist the practice, lest the word “irradiated” on the label scare off customers.
In case you think the argument for irradiation is part of a vast right-wing conspiracy, consider this Huffington Post article by the A.P.’s Lauran Neergaard, titled “Is Irradiation The Future Of E. Coli Prevention?”
The Rich vs Poor Debate: Are Kids Normal or Inferior Goods?
Are you likely to have more kids if you are rich or poor? Or to put this in econo-jargon: Are kids normal or inferior goods? (Reminder: When you get rich you buy more of a “normal good,” and less of an “inferior good.” And yes, the language of economics can be a bit cold.)
This is a question that’s central to a debate between Betsey Stevenson and Bryan Caplan. Recall, Bryan is the guy who argues that having kids needn’t be as expensive or time-consuming as we make them. Fair enough. But he then makes the leap to arguing that we should all have more kids. In her response, Betsey noted:
Caplan is entirely focused on the substitution effect: having kids becomes cheaper relative to buying TVs. So he says buy more kids, and fewer TVs. But what about the income effect? As people become richer, they tend to “buy” fewer children, not more. So there’s an offsetting income effect.
In a follow-up, Bryan runs some regressions that he thinks suggest that Betsey is wrong to say that the rich have fewer kids than the poor. It’s a brave person who debates Betsey on the data. And I think he’s tying himself in regression knots, rather than getting at the issue. Read More »
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This week: Does having a full bladder help you make more rational decisions? A survey of the best Civil War facial hair; why wheat beer is good for marathoners; and whether the Consumer Financial Protection Bureau is the largest field study ever in behavioral economics. Read More »
and 
. If you haven’t seen it yet, the movie features Steven Levitt and Stephen Dubner, and was made by a dream team of documentary directors. Paste Magazine named it one of the 