Explain each of the following statements in no more than three lines:

1. As a worker's nonlabor income rises, the likelihood that she will participate in the labor force declines.

2. For a worker to be at equilibrium, the marginal rate of substitution must be equal to the market wage.

3. During recessions, the unemployment rate underestimates the adversity of the labor market situation.

4. In Oman, the majority of working age migrants are employed, whereas the same is not true for locals.

5. Unlike the supply of a consumable good, the supply of labor may be negatively sloped.