"spending by households on many of modern life's "basics"—food at home, automobiles, clothing and footwear, household furnishings and equipment, and housing and utilities—fell from 53% of disposable income in 1950 to 44% in 1970 to 32% today."
There's a reason why the middle class today can buy so much MORE stuff, it's all much cheaper. The article is saying people are not richer, but the quality of life is not significantly different for the middle class then it is for the rich (the same access to long life, short travel, etc...)