How would you approach measuring this? Real GDP per capita is a poor measure due to wealth and wage disparities. Real Wages is a poor measure because it doesn’t account for asset prices nor cost of living (instead it’s a basket of goods and measures the purchasing power of the dollar, which is not the same thing). The Fed has a measurement “Mean Wages Adjusted by Cost of Living” but this is only region based and only goes back to 2008. To demonstrate a good standard of living, say the median person good support themselves, another adult, and 2 children on one income in 1980 while the median house cost 2X median wages. To demonstrate a poorer standard of living, say today the median person can support only themselves and one child on one wage (for example - I haven’t calculated this) and the median house costs 5X median wages.