Taxation of Social Security benefits under the new income tax provisions: distributional estimates for 1994.

The 1993 Omnibus Budget Reconciliation Act raised the proportion of benefits includable in income for the Federal personal income tax. This article presents estimates of the income-distributional effects of the new provision in 1994, the first year for which it is effective. Under the pre-1993 law, up to 50 percent of benefits were included in taxable income for certain high-income beneficiaries. Under the new law, some of these beneficiaries are required to include an even higher proportion of benefits--up to 85 percent. Only 11 percent of beneficiary families, concentrated in the top three deciles by family income, include more of their benefits in taxable income under the new law than they would have under the old law. Another 8 percent include the same amount of benefits under either. The remaining beneficiary families, more than 80 percent, include no benefits in taxable income under either the old law or the new.