The oligopoly model in which the businessman assumes that the competitors' output are fixed and simultaneously decide how much to produce is:

Question

Accepted Answer

The correct option is 1:
The **Cournot Oligopoly Model** accurately describes the scenario where firms simultaneously choose their output level while assuming their competitors' output quantities are fixed. This classic model, named after Antoine Augustin Cournot, is fundamental to understanding competition in oligopolistic markets. In the Cournot framework, firms produce a homogeneous product and act independently to maximize their own profits. The key behavioral assumption, known as the Cournot conjecture, is that each firm treats the production level of its rivals as a fixed given when deciding how much to produce. This simultaneous decision process leads to a Cournot-Nash equilibrium, where no firm has an incentive to unilaterally change its output, making the output decision the strategic variable that collectively determines the market price.

The incorrect option is 2:
The **Stackelberg Oligopoly Model** is distinguished by a sequential, rather than simultaneous, decision-making structure. In this model, there is a clear market *leader* who makes its output decision first, which is then observed by the *follower* firm(s). The leader profits from this "first-mover advantage" by anticipating the follower's reaction. Therefore, the assumption that competitors' outputs are fixed and decisions are made simultaneously is explicitly violated by the sequential nature of the Stackelberg model. The leader’s optimal output calculation explicitly incorporates the follower’s reaction function.

The incorrect option is 3:
The **Chamberlin's Oligopoly Model** is typically associated with monopolistic competition, where firms sell differentiated products, or a specific oligopoly case where firms fully recognize their mutual interdependence. When firms recognize their interdependence, they understand that a change in their own output will cause a change in their rival's output. This mutual recognition in his oligopoly model often leads to a solution that resembles a *collusive* or joint-profit-maximizing outcome, which contrasts with the non-cooperative and *fixed-output conjecture* that is the defining characteristic of the Cournot model.

The incorrect option is 4:
The **Bertrand Oligopoly Model** is incorrect because the strategic variable is **price**, not quantity. In the Bertrand model, firms simultaneously choose the price at which to sell their homogeneous product, assuming their rivals' *prices* will remain fixed. Because consumers will always buy from the lowest-priced firm, this competition typically drives the price down to the marginal cost, yielding a perfectly competitive outcome. This is a fundamentally different type of competition from the Cournot model, where the firms compete by choosing production quantities.