Implicit marginal tax Rates over 100%

"For many of the working poor, the implicit marginal tax rate is greater than 100 percent. The long-run consequence of undermining the positive incentive to work is, of course, the creation of an underclass acclimated to not working;"

Also it is not an accident.

Why do the government's implicit marginal tax rates go so far out of their way to affect people and households with low annual incomes? ... we see that aggregate household income first rises, then falls as income increases, with households at lower incomes collectively earning as much as the households at higher incomes. For example, we can directly observe that households with annual earnings of $20,000 amass the same amount of aggregate income as those with annual earnings of $80,000. ..... We find that the level of implicit marginal tax rates with respect to earned income look the way they do because of how most of the money earned each year is distributed among U.S. households. With a progressive income tax structure, implicit taxation through the phase-out of welfare and other income-based tax benefits and credits at lower income levels is the method by which the government would appear to shift the implicit tax burden to more closely center on the mass of money aggregated in households with annual earnings between $19,000 and $46,000.