[영문]The combination of a progressive tax system with credits for low?income workers and means?tested transfer programs can create high marginal tax rates (MTRs) on earned income. We documentthe extent and distribution of statutory and actual MTRs for Wisconsin households with earned income in 2000 using a unique data set of merged tax, transfer program, and wage data. Nearly aquarter of unmarried tax filers with two or more dependents face MTRs of 50 percent or greater. Households between 100 percent and 250 percent of the federal poverty threshold and those using multiple means?tested programs are more likely to face high rates.