(Oakhill Press, 2005), uses a hypothetical couple, both 65, who have an estate of $1.5 million, but taxable income of only $30,000, which puts them in a 15 percent tax bracket.

To understand why, let's look at a hypothetical couple in their 40's.

To test the program, data were entered for two hypothetical couples, each aged 43 and 45, with annual income of $90,000.

Like most married couples, this hypothetical couple - Samuel and Felicity Taxpayer - are filing jointly (Line 2).

Last year, Money magazine asked 50 tax preparers to complete the tax return of a hypothetical couple with three children who earned a combined salary of $100,000.

The city's Independent Budget Office, a nonpartisan city agency, came up with a hypothetical couple to explain the change.

Below the $200,000 level of the hypothetical couple, filers would pay the higher rate on less than all of their income.

With a taxable income of $145,360, the hypothetical couple, the Filers are in the new 36 percent marginal tax bracket.