It's inflation adjusted wages. As in adjusted for changes in average costs of living. Most people don't spend all their money on TVs. they spend it on food, housing, transportation, clothing and other things that existed in 1973. Furthermore, they adjust the inflation figure to account for changes in the technological utility of things
Life is not fundamentally different. Little details are different, but people still buy houses or pay rent, buy cars, buy food, pay for education, pay for entertainment, etc.
Well, I was assuming that people like engineers and programmers weren't "production". There are more of them now than there were in 1973, and fewer factory workers.
http://www.littlehouseinthevalley.com/cost-of-living-compari...