President Ronald Reagan cut income tax rates 10 years ago, thus continuing the postwar process begun by President John F. Kennedy of restoring our property rights to our own incomes. And the special-interest lobbies who live off the sweat of the taxpayer's brow have been screaming ever since.

According to them, the Reagan tax cuts made the rich richer and the poor poorer.Looking back after 10 years, where does the truth lie?

One way to arrive at an answer is to compare the income taxes we pay today with the amounts that would be due if the 1980 tax law still applied. Two former Treasury economists, Gary and Aldona Robbins, have provided the comparison.

In 1990, a $10,000 income paid on average $369 in federal income taxes. Under the pre-Reagan tax structure, the IRS would have extracted $863, or 134 percent more.

The income tax due on a $30,000 income in 1990 was $2,884. Under the 1980 law, the tax would have been $5,149, or 83 percent more.

Getting into the big bucks, a $175,000 income forked over $35,588 in 1990. Under the 1980 tax rates, the bill would have been $60,407, or 70 percent more.

The higher incomes clearly gained more from the tax cuts in terms of dollar amount, but that's because the incomes are larger. In proportional terms, the higher incomes gained the least from the 1981 tax cut.

These comparisons go a long way toward refuting the charge the Reagan tax cuts favored the rich, but they don't satisfy everyone. Some critics admit these figures are fine as far as they go, but point out that they do not include the increases in the Social Security payroll tax. They argue that cutting income tax rates while raising payroll tax rates shifted the tax burden from upper to lower incomes.

The Social Security tax increases did disproportionally affect lower incomes. Where the claim goes wrong is in blaming the higher Social Security taxes on Reagan. The bulk - 86 percent, to be precise - of the increase in payroll taxes during the 1980s was legislated in 1977. Automatic increases in the Social Security tax rate already were scheduled in the law for 1981, 1982, 1985, 1986 and 1990 before Reagan became president.

Jimmy Carter's administration had scheduled these increases in order to pay for the planned growth in Social Security benefits. However, the calculations were a little off, and in 1983 the Reagan administration accelerated some of the already scheduled increases after Congress refused to slow the growth in benefits to match the growth in payroll revenues.

Including the Social Security tax increases, however, the tax burden on a $10,000 income in 1990 is still 42 percent less than it would have been without the 1981 income tax cuts. The $30,000 income is taxed 40 percent less, and the $175,000 income is taxed 53 percent less.

This result is hardly surprising. Social Security benefits are capped and cannot be accrued on 1990 incomes above $51,300. Moreover, lower income workers receive a higher proportion of their pre-retirement income in Social Security benefits than do higher income workers.

The Reagan tax cut has proved to be good for us in many ways. Among its benefits, it caused companies to shave their expenses and become more competitive. During the 1980s, our industrial productivity growth tripled, the inflation rate collapsed and our exports rebounded to record levels. People earned more and, thanks to Reagan, got to keep more of what they earned.