What does a perfectly elastic demand curve indicate for a firm?

A perfectly elastic demand curve indicates that consumers are highly responsive to changes in price. In this scenario, the demand curve is horizontal, meaning that at a specific market price, consumers will buy any quantity of the product that is offered. However, if the price rises even slightly above this market price, consumers will not purchase any units of the product, as they can easily switch to substitute products.

Thus, the correct interpretation is that consumers will only buy at the market price. This captures the essence of perfect elasticity, where any deviation from the market price results in a complete loss of demand for that firm's product. This situation typically occurs in highly competitive markets where numerous substitutes are available, reinforcing the idea that firms cannot set their prices above the prevailing market rate without losing all their customers.