Duopoly can also be examined experimentally as a market, with two sellers and several buyers. This page describes a duopoly market that is similar to the duopoly game, except that rather than a constant marginal cost for the sellers, the duopoly market example that we develop has marginal costs that increase. This change is introduced so that it will be easier to compare duopoly to a standard example of a competitive market and also to a standard example of a monopoly market.

Figure 1 shows the monopoly price and quantity and the competitive price and quantity for experiments with the same marginal cost schedules and marginal value schedules that we use in our duopoly market experiment. By using the same marginal cost and marginal value schedules, we can make a direct comparison between these three different market structures.

From the diagram we can see that the competitive price is p_c = 24 and the competitive quantity is q_c = 20, 21, or 22. The monopoly price and quantity for these marginal cost and value schedules are worked out on the monopoly page. The monopoly price is p_M = 32 and the monopoly quantity is q_M = 14.

For this duopoly market, there is an argument included on the page with the experiment configuration which shows that the duopoly price and quantity for these margainal cost and value schedules are approximately p_D = 28 and q_D = 17.

Experiments on the duopoly market model are included in MarketLink for both the double auction and the posted offer auction. If you haven't yet used MarketLink to run an experiment, go to the MarketLink page for information. If you are familiar with MarketLink, you can add these experiments to you profile from the duopoly market experiment configurations page.

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