Which of the following is not one of the four types of goods classified by excludability and rivalry?

• A. Public goods
• B. Monopolistic goods
• C. Private goods
• D. Common resources

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the classification of goods based on two key characteristics: excludability and rivalry. Excludability means whether people can be prevented from using the good, and rivalry means whether one person's use of the good reduces its availability to others.
2. Step 2: Recall the four standard types of goods in microeconomics: Private goods (excludable and rival), Public goods (non-excludable and non-rival), Common resources (non-excludable but rival), and Club goods or Toll goods (excludable but non-rival).
3. Step 3: Identify that 'Monopolistic goods' is not a standard category based on excludability and rivalry. Instead, monopolistic competition refers to a market structure, not a type of good.
4. Step 4: Compare each option to the standard classification: Public goods, Private goods, and Common resources all fit into the four types, while Monopolistic goods do not.
5. Step 5: Conclude that the correct answer is the one that does not fit into the classification system based on excludability and rivalry, which is 'Monopolistic goods'.