Division of things into shares or portions, To goods that are bought and used together, When a consumer is able and willing to buy a good or service, Graphic representation of the demand schedule, Describes demand that is very sensitive to a change in price, Latin phrase that means all other things held constant, Luxury, A type of good that might not be bought when prices rise, Level of production in which the marginal product of labor decreases as the number of workers increases, and Measure to how consumers react to a change in price.