[MUSIC] Now, let's do the opposite direction. Suppose that the market price is very low. So the firm, when it maximizes profit, is actually making a loss. Again, this is the market price, and the individual firm takes that as given, because marginal revenue is equal to the price. The firm maximizes profit by choosing where marginal revenue equals marginal cost, which is this quantity here. But we can see that the firm is losing money because the price is less than the average total cost, and here are the firm's losses. We said that the firm might choose to produce in the short run, because at least, it's helping pay down some of the fixed costs. But in the long run, the firm will choose to exit the market. And as firms choose to exit the market, the supply curve is going to shift in. So some firms leave the market, and as some firms leave the market, the supply curve shifts in. And as the supply curve shifts in, the price starts to go up. So those firms who are still in the market are starting to see a little bit of an improvement in their life, because the price starts to go up. And this process will continue until those firms who are in the market are making zero profit, in other words, when price is equal to the average total cost. Let's go ahead and summarize this.