I The demand schedule indicates the amount of a good that consumers would be willing to buy at each potential price. The first law of demand states that the quantity of a product demanded is inversely related to its price. A reduction in the price of a product reduces the opportunity cost of consuming it. At the lower price, many consumers will substitute the now cheaper good for other products. In contrast, higher prices will induce consumers to buy less as they turn to substitutes that are now relatively cheaper.