One possible change would tax the entire salary earned by those making more than a certain level — $400,000 or so — at the top rate of 35 percent rather than allowing them to pay lower rates before they reach the target, as is the standard formula. That plan would allow Republicans to say they did not back down in their opposition to raising marginal tax rates and Democrats to say they prevailed by increasing effective tax rates on the rich. At the same time, it would provide an initial effort to reduce the deficit, which the negotiators call a down payment, as Congressional tax-writing committees hash out a broad overhaul of the tax code.

That idea could be combined with the reinstatement tax code provisions that once prevented the rich from taking personal exemptions or itemizing deductions. Those rules were eliminated by the tax cut of 2001. Reinstating them would tack an additional one to two percentage points onto the effective tax rates of high-income households without raising the 35 percent rate, but which households would be affected has not been decided. In all, tax experts say, families in the top tax bracket would find their effective tax rate jump to 41 percent, even though the top statutory rate would remain 35 percent.