Song earns $100,000 taxable income as an interior designer and is taxed at an average rate of 20 percent (i.e., $20,000 of tax). If Congress increases the income tax rate such that Song's average tax rate increases from 20 percent to 25 percent, how much more income tax will she pay assuming that the income effect is descriptive? What effect will this tax rate change have on the tax base and tax collected?