This article from the New York Times assumes that household consumption is a better indicator of Americans’ living standard Than income. This idea is based on the Bureau of Labor Statistics that say that the bottom fifth earned just  $9,974 but spent an average of $18,153 a year. I copied below the explanation provided:

How is that possible? A look at the far right-hand column of the consumption chart, labeled “financial flows,” shows why: those lower-income families have access to various sources of spending money that doesn’t fall under taxable income. These sources include portions of sales of property like homes and cars and securities that are not subject to capital gains taxes, insurance policies redeemed, or the drawing down of bank accounts. While some of these families are mired in poverty, many (the exact proportion is unclear) are headed by retirees and those temporarily between jobs, and thus their low income total doesn’t accurately reflect their long-term financial status.

Taking consumption as indicator instead of incomes, reduces the gap between top fifth and  bottom fifth to 4 to 1. This ratio is 15 to 1 if incomes is used as indicator.

You Are What You Spend - New York Times via kwout