Well don't forget the definition of living comfortably is far different now than in 1970. Houses are bigger, cars are fancier and have actual safety features plus something other than an airvent and an AM radio, there are now multiple tvs in the house and they are not only in color but the biggest in the house is no longer 19" and they get more than 3 channels, computers, computers, computers, video game machines, home exercise equipment, there is no longer just one phone in the house that you rent, people belong to gyms other than a YMCA, you don't just go out to eat on special occasions, etc.