We examine the proposition that competitive firms must behave as if they were maximizing profits; otherwise they would go bankrupt, or even fail to be financed in a competitive capital market. We investigate a model in which an entrepreneur raises funds for a risky enterprise on a competitive capital market, by offering a “dividend policy” based on the realized (stochastic) flow of earnings. We show that an entrepreneur who maximizes the expected sum of discounted dividends is sure to fail in finite time. On the other hand, many other behaviours yield positive expected profits and are able to attract investment funds, and yet result in a positive probability of surviving forever. As a consequence, if new firms have sufficiently diverse behaviours, then even if there is a constant stream of new entrants, after a long time practically all of the surviving firms will not have been maximizing profits.

This article develops a game‐theoretic model to analyze market makers' intertemporal pricing strategies. We show that dealers who adopt noncooperative pricing strategies may set bid‐ask spreads above competitive levels. This form of “implicit collusion” differs from explicit collusion, where dealers cooperate to fix prices. Price discreteness or asymmetric information are not required for collusion to occur. Rather, institutional arrangements that restrict access to the order flow are important determinants of the ability to collude because they reduce dealers' incentives to compete on price. Public policy efforts to increase interdealer competition should focus on such restrictions.