Does it pay to work more hours in order to earn more income?  That’s the question posed in a new study by the National Center for Policy Analysis:

Virtually all American households are confronted with high to very high marginal tax rates when they increase the number of hours they work in the current year or in future years.  Much of the system’s highest effective marginal taxation comes courtesy of government transfer programs, particularly Medicaid.  In fact, penalties for working are astronomical for some households, particularly lower-income families.

Emphasis mine. More here.