As an economist and professor, Emily Oster is accustomed to using data to inform the decisions that she made in her own life. When Emily got pregnant with her daughter, Penelope, she was shocked by the lack of data provided by doctors to back up the common rules of pregnancy. Emily started to analyze the data behind many common pregnancy rules, and wrote a book, Expecting Better to improve decision-making for pregnant women. As her kids have grown up, her research has continued through 2 subsequent books, Crib Sheet, focusing on birth to preschool and Family Firm, which comes out today, focusing on the early school years.