When firms act as if they had an agreement this is called explicit quotas. oligopoly. tacit collusion. a cartel.

Break Down the Problem

1. Identify the Key Terms: Look for definitions or characteristics of the terms provided.
2. Analyze the Options: Examine each option to understand their meanings and context in economic theory.

Relevant Concepts

1. Explicit Quotas: Formal agreements between firms specifying how much each firm will produce.
2. Oligopoly: A market structure dominated by a few firms, where each firm's decisions affect the others.
3. Tacit Collusion: An implicit agreement among firms to coordinate their actions without formal communication.
4. Cartel: A formal agreement among competing firms to control prices or production.

Analysis and Detail

• Explicit Quotas imply a clear, formal agreement, which does not align with the issue at hand where firms act as if they have an agreement without direct communication.
• Oligopoly describes the market structure but does not directly reflect the cooperative behavior implied in the question.
• Tacit Collusion is characterized by firms behaving cooperatively without explicit communication and agreeing on market strategies implicitly.
• Cartel involves direct, formal agreements, making it less applicable to the definition implied.

Verify and Summarize

The term that most appropriately describes the situation where firms act as if they had an agreement without explicit coordination is "tacit collusion".

Final Answer

The correct answer is tacit collusion.