Free Markets and Market Failures

Steps:

• Identify market failures: Demerit goods (negative externalities, e.g., tobacco), merit goods (underconsumed positives, e.g., education), public goods (non-excludable, e.g., defense).
• Recall free market efficiency: Achieved in perfect competition without externalities or public goods, per Pareto optimality.
• Evaluate options: Efficiency requires absence of these failures to avoid misallocation.
• Select condition with zero such goods for pure market operation.

Why D is correct:

• No demerit/merit goods or public goods means no externalities or free-rider issues, allowing prices to signal true scarcity and achieve efficient allocation via supply-demand equilibrium.

Why the others are wrong:

• A: Few of each still causes some misallocation from externalities and non-provision of public goods.
• B: Many demerit/merit goods amplify externalities, distorting efficient resource use.
• C: Many merit goods lead to underproduction without intervention, preventing efficiency.

Final answer: D