Similarly, the reverse movement represents a decrease in demand. The beauty of the connection between demand and marginal value is that an increase in demand could in principle have meant either more units demanded at a given price, or a higher willingness to pay for each unit, but those are in fact the same concept – both create a movement up and to the right. For many goods, an increase in income increases the demand for the good. Porsche automobiles, yachts, and Beverly Hills homes are mostly purchased by people with high incomes. Few billionaires.
