I like that you relate purchasing power to gold, and you could also look at silver. I think the flaw is that Americans are not paid in gold or silver and have not been over that time. Our money has been debased and the high price of gold and silver is a symptom of that.
Consider Henry Ford’s $5 work day. At the time gold was worth $20 per ounce. So unskilled labor was earning about $425 per day in terms of gold today. That comes out to $110,500 per year. How many unskilled laborers are making even half that today?
Another example from 1963 using silver. When my mom got her first teaching job out of college that year, she was paid $100 per week for 40 weeks of teaching. A silver dollar was 90% silver at that time. So she was being paid 90 ounces of silver per week. 90 ounces x 40 weeks x $35 per ounce in today’s dollars would be $126,000 per year for a teacher right out of college.
These two examples show just how poor and how little purchasing power the average American has relative to what they had in the past. This is why we need a two income family to have the same lifestyle as a single income family had in the past.
Oops, a silver dollar (Morgan, Peace dollars, two halves, four quarters, ten dimes--all the same amount) is only .72 ounces of silver, not an ounce. $90,720/year would be more correct (still, not bad).