If we had eight-hour workdays a century ago, we wouldn't have been able to support the standard of living expected a century ago.

Is that true? (Technically, a century ago was 1912.)

Wikipedia on the eight-hour day:

On January 5, 1914, the Ford Motor Company took the radical step of doubling pay to $5 a day and cut shifts from nine hours to eight, moves that were not popular with rival companies, although seeing the increase in Ford's productivity, and a significant increase in profit margin (from $30 million to $60 million in two years), most soon followed suit.