The portion of double income households more than doubled between 1960 and today[1]. The middle class is working more because they want to, or because they need to? Purchasing power for the average worker is flat[2]. In some sense, it's like the middle class has been working for fifty years without a raise, only now two people in the household need to work. That fewer people are getting married or having kids is likely not because human nature shifted in the past few decades, but probably because their lives are not going well or developing properly.

1 - https://www.pewresearch.org/ft_dual-income-households-1960-2... 2 - https://www.pewresearch.org/fact-tank/2018/08/07/for-most-us...

> Purchasing power for the average worker is flat[2]. In some sense, it's like the middle class has been working for fifty years without a raise, only now two people in the household need to work

That “flat” wage is accounting for inflation according to your own link. So not only would a single earner be doing just as good today as back then, adding a second income means they are raking in twice the spending power as back then.

The only thing that has changed are expectations. People want way bigger houses, nicer cars, computers, smart phones, more meat, dental care, better medical care, etc. Worst of all (from a financial perspective), they want both of their average kids to spend 4 years at an expensive university.

> Worst of all (from a financial perspective), they want both of their average kids to spend 4 years at an expensive university.

Expensive only because it's been allowed to become expensive. Decades ago it was normal for a good university to be nearly free or at least quite affordably by the student working part time to pay their way.

> dental care, better medical care

People "want" health care. I mean of course, but it's not a whim, it's a basic necessity. Which like the university, was very affordable to nearly everyone decades ago.

Not sure people want bigger houses either, every housing topic on HN is full of desire for smaller apartments to get built.

> Decades ago it was normal for a good university to be nearly free or at least quite affordably by the student working part time to pay their way.

Here's a few graphs that show this more explicitly: https://www.buzzfeednews.com/article/gregschoofs/how-much-co...

Indeed. Even as late as the early 90s, my summer internships (not at minimum wage, but still just intern pay) was almost enough to pay for a year of tuition at CMU, an expensive top university.

> The portion of double income households more than doubled between 1960 and today[1].

Your data only represents "married couples with children under 18"--a (shrinking) minority of households. By definition it does not account for the dramatic rise in single-adult households.

The single adult households are a separate and bad thing. I don't think there has been a substantial shift in human desires in the last couple generations - most people still want to get married and have kids and fewer of them are. That they are able to subsist in one family households is not a bragging point for our system.