Bertrand competition under decreasing returns involves a wide interval of pure strategy equilibrium prices. We first present results of experiments in which two, three and four identical firms repeatedly interact in this environment. Less collusion with more firms leads to lower average prices....

We study collusive behaviour in experimental duopolies that compete in prices under dynamic demand conditions. In one treatment the demand grows at a constant rate. In the other treatment the demand declines at another constant rate. The rates are chosen so that the evolution of the demand in...