Since firms cannot explicitly coordinate on setting price, they use implicit means. One form of implicit collusion is to follow a price leader. The price leader, often the largest or dominant firm in the industry, determines its profit-maximizing quantity by calculating the demand curve it faces as follows: at each price, it subtracts the quantity supplied by all other firms from the market demand, and the residual is its demand curve. The leader chooses the quantity that equates its marginal revenue with its marginal cost and sets price to sell this quantity. The other firms (the followers) match the leader’s price and supply the remainder of the market.