Powerful currents have reshaped the structure of families over the last century. There has been (i) a dramatic drop in fertility and greater parental investment in children; (ii) a rise in married female labor-force participation; (iii) a decline in marriage and a rise in divorce; (iv) a higher degree of assortative mating; (v) more children living with a single mother; (vi) shifts in social norms governing premarital sex and married women’s roles in the labor market. Macroeconomic models explaining these aggregate trends are surveyed. The relentless flow of technological progress and its role in shaping family life are stressed. 1.

We thank Andres Blanco for excellent research assistance and Richard Blundell and seminar audiences for helpful comments. This research was funded in part by the NSF. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peer-reviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.