1960, Peak Cohabitation for Young Adults in the United States

If the 1950s were peak city (in terms of population) in the United States, the decade also represented peak cohabitation for young adults (18-34 year-olds). "For First Time in Modern Era, Living With Parents Edges Out Other Living Arrangements for 18- to 34-Year-Olds":

Dating back to 1880, the most common living arrangement among young adults has been living with a romantic partner, whether a spouse or a significant other. This type of arrangement peaked around 1960, when 62% of the nation’s 18- to 34-year-olds were living with a spouse or partner in their own household, and only one-in-five were living with their parents.

Back in the 1880s, an agricultural economy tipped industrial. In the 1950s, a blue collar economy tipped white collar. In the 2010s, a white collar economy is tipping white coat. These economic shifts are reflected in the household composition changes for young adults.

For women, the trend since 1960 is one of increasing labor market share. For men, it is a steady fall from a zenith of economic power. One important result is a dearth of two young adults sharing a one bedroom apartment in a city.

Those couples sharing a bed are likely college-educated and well remunerated, thus punishing young adults requiring solitude for slumber in the urban rental market. Bottom line, the same number of people in 1960 would require more city rooms in 2014. The sun will shine on two couples, all four working, sharing a two bedroom flat. They will have the pick of the real estate litter.

The social arrangements during peak city (1950s) define today's housing cost challenges. Why pack into tenements when inner ring suburbs drown in affordable single family housing? Immigrants have figured this out. The native born would rather pay the cool city price or move back in with mom and dad.