______ is a type of oligopoly, characterised by two primary corporations operating in a market or industry, producing the same or similar goods and services. 

The correct answer is Duopoly.

Key Points

• A duopoly is a type of oligopoly where only two firms dominate the market.
• These two firms produce identical or similar goods and services.
• Duopolies can lead to competitive or collusive behaviors between the two firms.
• Market outcomes in a duopoly can be analyzed using game theory, particularly the Cournot and Bertrand models.
• Duopolistic markets often exhibit significant barriers to entry, preventing other firms from entering the market.

Additional Information

• Perfect Competition
  • This is a market structure characterized by a large number of small firms, homogenous products, and easy entry and exit from the market.
  • In perfect competition, no single firm can influence the market price.
• Monopoly
  • A monopoly is a market structure where a single firm dominates the entire market.
  • This firm is the sole provider of a particular good or service, with high barriers to entry preventing other firms from entering the market.
• Monopsony
  • In a monopsony, there is only one buyer in the market, giving this buyer substantial control over prices and terms of purchase.
  • This market structure is the opposite of a monopoly, which features a single seller.