I have a hard time believing that our 'standards' constitute the major need for 2 salaries. A simple thought experiment seems sufficient to debunk this...

The average salary in CA is ~62k a year. To support a family of 4 (wife + 3 kids) you would need WAY more than $62k.

Even if you lived in the poorest neighborhood, and never bought frivolous things, you could still never support a family on that salary, and forget about buying a house.

In the 1950s you could support a family, buy a house, pay for healthcare, etc. It seems far more plausible to me that the purchasing power domestically of the dollar was effectively halved at some point in history.

My guess is that you're wildly overestimating the average 1950s standard of living. In many ways, lower-income folks have better lives today than even the wealthy did back then. You talk about healthcare, but healthcare in the 1950s was practically non-existent by modern standards. You can choose to live in a low cost-of-living area and your $62k will stretch a lot further than in any city "neighborhood".

I probably am overestimating the average 1950s standard of living. But I'd argue you're also overestimating how far $62k could take a family of 5 in CA. Even in the poorest of neighborhoods, far outside of city centers (where you probably wouldn't even be making $62k btw)... even then... I highly doubt you could support a family of 5, and I can guarantee that you would not be buying a house.

I maintain that both of these things were (generally) more accessible in the 1950s.

> The reason why families need two incomes nowadays is that our standards for what's "needed" have grown

Nope! It happened almost instantly after Bretton Woods system collapsed. And that wasn't because our living standards changed much, it's cause practically unbounded monetary inflation was embraced as the new standard.

Instead of benefitting from the price deflation afforded by technological progress, governments decided to debase their currencies to finance their centrally planned schemes. Combined with the relatively high transaction cost of finding a new job gave us a world where wages have stagnated.