Not just the poor live hand-to-mouth

Stimulus programs -- such as those in 2001, 2008 and 2009 -- are designed to boost the economy quickly by getting cash into the hands of people likely to turn around and spend it.

But sending cash to just the very poor may not be the right approach, according to researchers from Princeton University and New York University who analyzed information on the finances of U.S. households from 1989 to 2010.

"What we found is that households that have the lowest liquid wealth -- where liquid wealth is defined as basically anything other than housing and retirement accounts -- tend to spend a large part of their stimulus checks, but many of those households aren't the poorest in terms of income or net worth," said Greg Kaplan, an assistant professor of economics at Princeton. "That's the group we call the wealthy hand-to-mouth."

Thirty to 40 percent of U.S. households live hand-to-mouth, consuming all of their disposable income. Two-thirds of those households fall into a category described as the "wealthy hand-to-mouth," according to the work by Kaplan, Giovanni Violante, the William R. Berkley Term Professor of Economics at New York University, and Justin Weidner, a graduate student in economics at Princeton.