The amount of labor that workers supply is generally considered to be positively related to the nominal wage; as wage increases, labor supplied increases. Economists graph this relationship with the wage on the vertical axis and the quantity of labor supplied on the horizontal axis. The supply of labor curve then is upward sloping, and is depicted as a line moving up and to the right.

The upward sloping labor supply curve results from the fact that, as wages rise, people in the labor force are incented to spend less time in leisure and more time working while people outside the labor force are incented to join the labor force. As wages rise, the cost of spending time in leisure and the cost of not being a labor force participant rises.