Wealthy Americans would bear the lightest share of the burden imposed by the new $500 billion deficit-reduction plan, while the poorest people would shoulder the greatest costs, a congressional study says.

The richest one-fifth of American families, with annual after-tax income averaging $81,934, would lose 0.9 percent of their earnings as a result of the plan. That would come to a $766 loss.But the poorest one-fifth of Americans would lose 2 percent of their average $7,316 annual after-tax incomes, or $148, according to the study by the House Ways and Means Committee.

The average American family would suffer a 1.2 percent hit. Its $33,401 average after-tax income would shrink by $394.

The analysis seems to show that one of the priorities Democrats touted during their four months of budget negotiations with the Bush administration - a package that spreads the burden based on people's ability to pay - was not achieved.

The study analyzed the effects of the higher taxes and benefit program cuts the package would impose. These include levies on luxury items, tobacco, alcohol, fuel, airline tickets and the incomes of people who earn more than $100,000 annually.

The package also applies the 1.45 percent Medicare tax to people with incomes of up to $73,000, rather than the current $51,300. It increases the monthly $28.60 premium Medicare recipients pay for doctors' care by about $5 and doubles the $75 deductible beneficiaries themselves pay for physicians' bills.

It provides a number of tax breaks for businesses and expands the earned income tax credit for the poor.

It also requires states to impose two-week waiting periods for people waiting to collect unemployment benefits.

The study also concluded that:

- For families in the second-lowest fifth of annual income, averaging $16,917, the loss would be 1.6 percent, or $272.

- For families in the middle fifth, averaging $25,896, the loss would be 1.3 percent, or $347.

- For families in the second-highest fifth, or an average of $36,481, the loss would be 1.1 percent, or $416.