I want to make sure people can live comfortably on the money they can earn in 20 hr/week. If want to work 60 hr/week for 15 years and then retire early good for them. I just want to make 20 hr/week the norm.
It doesn't work like that... many of life's biggest expenses are priced based on market rates (e.g. housing). If more work is available and some people choose to work more hours, they will be able to outbid tier who don't and drive up the cost of living.
