People Are Waiting Longer to Get Married

One of the central points raised by the theory of the Second Demographic Transition is that young people in richer countries are growing up with ideas of what to do with their lives besides the time-honored tradition of marrying and having kids. Today the U.S. Census Bureau reminded us of this trend with data from the Current Population Survey. Here's the pattern over time in average age at marriage for males and females in the U.S.:

The graph starts back in 1890 when the rise in the age at marriage (relative to earlier years not shown in the graph) was associated with the beginning of the decline in fertility. This was prior to the advent of effective methods of contraception, so delaying marriage (which in those days also meant delaying the onset of sexual activity) was a way of limiting fertility. The post-WWII period changed all of that and set in motion a round of early marriage and childbearing that produced the baby boomers. But the younger generations have been consistently delaying marriage, although not necessarily delaying sexual activity. In the process, they are creating a very different set of family and household relationships than we've experienced before. This is, of course, why family demography is such a key element in modern social science.