Which characteristic applies to private goods but not to public goods?

• A. Rivalry in consumption
• B. Not excludable
• C. Non-excludable
• D. Non-rivalrous consumption

Answer: (A)

Rivalry in consumption is the key idea. For private goods, one person using the good reduces the amount available for others (like a slice of pizza—you can’t eat the same slice twice). Public goods, on the other hand, are non-rivalrous: one person’s use doesn’t significantly reduce another’s ability to enjoy the same good (think of national defense or clean air).

That’s why the characteristic that applies to private goods but not to public goods is rivalry in consumption. The other options describe features of public goods (not excludable, non-excludable, non-rivalrous) or conflict with how private goods work (private goods are excludable and rivalrous, not non-excludable or non-rivalrous).