We focus on effective marginal tax rates as people move between various levels of
poverty ranging from no work to earnings at twice the FPL. Although effective marginal
tax rate calculations are often evaluated in terms of the impact of an additional dollar
of earnings, few workers can make incremental decisions that affect only one dollar
earned at a time, making the value of effective marginal tax rates calculated in this
manner somewhat unclear. It is more likely that families receive additional income in
increments derived from an increase in the number of hours they work, or a fixed wage
rate increase (for example, their current employer could offer them more hours or they
might receive a pay increase).