This doesn't make sense at all. It is a bad statistical analysis of consumer spending. [1] A few things from the thread on why by Levy on why it feels wrong .
First, why does it feel wrong?
1. the top 10% get about 50% of pre-tax income
2. they get 30 to 37% of disposable income after tax&transfers (depending on source)
3. and we know the rich have a higher savings rate, so consume a lesser share of their income (US, China)