The Economist:

For new parents, it is a terrifying moment. The hospital doors close behind them, leaving them with a new and helpless human being. The baby’s survival into adulthood seems impossible. What if it will not eat? What if it is allergic to water? What if an owl carries it off? Probably, few parents wish at that moment for the help of an economist. But “Cribsheet”, a new book by Emily Oster of Brown University, shows that in the hectic haze of parenthood an economist’s perspective can prove surprisingly clarifying.

Ms Oster’s academic work relates to health and health policy. A recent paper, for example, studied how food-purchasing decisions change in response to being diagnosed with diabetes. Five years ago she published a book on pregnancy, drawing on her training as an economist and her own experience (her husband, Jesse Shapiro, with whom she has two children, is also an economist at Brown). “Cribsheet” tackles the next step in the journey from childfree person to parent. Deciding whether to have a child in the first place fairly obviously involves economic calculations, from the impact on the parents’ earning potential to the resources that must be set aside to pay for nappies, child care and university. The decisions that come in a torrent after the birth, in contrast, such as whether to breastfeed or how to manage sleeping arrangements, might not seem so amenable to such thinking. But Ms Oster’s new book shows that they are.

Parents generally try to maximise the welfare, present and future, of their children (and, secondarily, themselves) subject to constraints of money and time. That requires choices. Economics can help a parent judge these trade-offs. Good choices begin with good information. Before deciding whether breastfeeding is worth the time, trouble and physical toll, it helps to know the benefits compared with feeding with formula. Parents do as most people do when making a hard call: turn to experts, friends, family and the internet. But different sources provide wildly different answers—and often with an extraordinary intensity of belief. As Ms Oster notes, internet mums frequently write as though ignoring their advice is tantamount to abandoning a child to wolves.