Robert Dunn's Aug. 20 op-ed column, "Good Reasons for a Tax Cut," rests on shaky ground.

He argues that because the top 10 percent of taxpayers pay 62.5 percent of income taxes, they should expect a similar share of tax cuts. But, according to IRS figures, this group's share of total federal taxes is actually less than 50 percent, and the Republican bill provides them with well above 62.5 percent of its benefits.

Mr. Dunn claims that changes in the income tax structure have negatively affected middle-class families. But as a share of their income, the bottom 80 percent of filers pays the same or less in taxes today than in 1990. So Mr. Dunn's aggrieved "middle class" is drawn, unaccountably, from the top 20 percent of tax filers.

He says the top tax rate, which applies only to the top half-percent of filers, exceeds 39.6 percent in light of the payroll tax. In fact, for capital gains income -- the major source of revenue for the rich -- the maximum tax rate is 20 percent and can be much lower if legal loopholes are applied.

Mr. Dunn contends that the United States is a high-tax nation. In fact, a recent study by the Organization for Economic Cooperation and Development shows the United States to have extremely low personal income tax rates compared with other industrialized nations.

His main concession to critics of the congressional proposal is that tax cuts would be ill-timed in the current economic boom. But in light of high budget surpluses forecasted by the Congressional Budget Office, reductions could be safely phased in over the coming decade.

On the whole, there is far less justification for tax cuts than Mr. Dunn implies. For roughly 60 percent of taxpayers, income taxes have decreased since 1990. For another 20 percent, they have increased on average by a tenth of a percentage point. Small wonder that polling shows scant enthusiasm for the cause of tax relief.

MAX SAWICKY

Silver Spring

The writer is an economist at the Economic Policy Institute.