In particular, lower rates at the top will widen the net income distribution, unless the reform is accompanied by measures that broaden the tax base to an extent that prevents average tax payments for rich families from falling. Without accounting for any tax-base changes, lower top income-tax rates exacerbate the widening gap between incomes at the bottom and the top of the distribution. Reductions in top rates were steepest in Japan (from 70 to 37 percent), Italy (65 to 43), United Kingdom (60 to 40), and France (65 to 48).