The share of income going to higher-income households rose, while the share going to lower-income households fell.
"But unless higher-income households start to save more, it will be a big concern."
The proposal would do nothing for couples who itemize their deductions, as most higher-income households do.
Moreover, the researchers found that a significant portion of higher-income households save little.
The same higher-income households that rely the most on e-mail correspondence also send and receive the most letters.
About 90 percent of the higher-income households have either one or two members.
The Census Bureau said that 8.1 percent of these higher-income households were uninsured last year, up from 7.6 percent in 1996.
This project sets out to discover how members of higher-income households decide who takes employment, of what kind, for what hours and on what terms.
When higher-income households leave one set of units, they abandon both shelter and neighborhoods.
"The Internet will be in every middle-class and higher-income household in the country."