The current practice of measuring age as years-since-birth, both in common practice and in the law, rather than alternative measures reflecting a person's stage in the lifecycle distorts important behavior such as retirement, saving, and the discussion of dependency ratios. Two alternative...

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 significant decline in marriage and a rise in divorce; (iv)...