What does the evidence suggest about breast feeding? I don't think it's as cut and dried as the BBC article pithily states: "years of research has found breast milk to be healthier than other substitutes." While we wait for somebody like Emily Oster to sift through the medical advice for us in her forthcoming book, here are some references I found helpful.
As you might imagine, there are few studies that are able to isolate the effects of breast feeding from family leave, which tends to increase breast feeding.
- Baker and Milligan (JHE, 2008) examine changes in Canadian maternity leave and find relatively little evidence of any effects on children's well-being within the first 24 months.
- Fletcher (Health Econ., 2011) looks at long-term educational outcomes and self-reported (retrospective!) breast feeding in the Add Health panel. He finds that differences in outcomes associated with breast feeding appeared to be driven by differences in parental behavior like treating siblings equally.
- Colen and Ramey (Soc Sci Med, 2014) assess patterns in outcomes among children in the NLSY across a broad age range, 4 to 14, associated with breast feeding. They report that benefits were mostly associated with parental characteristics, which prompted their selection into breast feeding.
- Lichtman-Sadot and Bell (JPAM, 2017) look at the introduction of paid family leave in California in 2004 and compare cohorts of children born before and after the policy change. They report large effects of paid family leave on 6 health metrics observed mostly via parental self-report at Kindergarten.
I would say there is some evidence that family leave can improve outcomes, but there is not much evidence to suggest that the primary channel is breast feeding.
