[aaronschroeder]

How much of this is due to the growth in labor force in general and the prevalence of dual income families. See: https://www.dol.gov/agencies/wb/data/facts-over-time/women-i....

If you go further back (50s - 60s), it was very common for a household to survive on a single income. Even 30-40 years ago when I grew up, our family of 6 lived off a single income from a non-college graduate.

That's very hard to do now, except for certain fields like tech.

[duderific]

That's pretty much the exact premise of the OP. Specifically, the growth in labor force/prevalence of dual income families was driven by the increase in costs, not the other way around.