Earlier quoted context omitted.
In 1930 my grandfather bought his house for $20K. So one years salary. But in 1930 people spent 80 percent of their monthly income on food. So house costs have gone up dramatically and food costs have gone down dramatically (as a proportion of income). So even if consumption were to have remained the same, the costs of things would still adjust forcing people to work closer to 40+ hours a week.
$20K of todays money or 1930s? because: > In 1930 the average American earned $1,368/year which is roughly $19,500/year in todays dollars. True about the expense shift. Today food is probably as cheap as it have ever been, and rent/real-estate is as expensive as it have ever been. :)
[src - not sure about the credibility, but it's good enough for me and this discussion] https://www.slideshare.net/mobile/bentleytran/living-cost-of...
There's a general problem with using averages anyway. As I see it an average wage/cost does not actually equal a normal cost which I believe is more important. That is the most common occurrence of something is often distorted by the averaging out process. So I don't put a lot of stock in using them.
Overall I'm pretty sure a few things happened:
1. Product costs went down due to cost reductions (found via economies of scale within manufacturing) and things like sugar manufacturing.
2. Money saved from General goods went into fuelling house price surges. i.e. People don't have bidding wars over food they just buy them at market price, but houses are different, they immediately are driven up with no regulation and lower supplies.