Would a significant increase in the top income tax rate substantially alter income inequality?

The high level of income inequality in the United States is at the forefront of policy attention. This paper focuses on one potential policy response: an increase in the top personal income tax rate. We conduct a simulation analysis using the Tax Policy Center (TPC) microsimulation model to determine how much of a reduction in income inequality would be achieved from increasing the top individual tax rate to as much as 50 percent. We calculate the resulting change in income inequality assuming an explicit redistribution of all new revenue to households in the bottom 20 percent of the income distribution. The resulting effects on overall income inequality are exceedingly modest.