Unlike a private good, a public good is characterized by which of the following?

• A. It is rivalrous but non-excludable.
• B. It is non-rivalrous and non-excludable.
• C. It is rivalrous and excludable.
• D. It is non-rivalrous but excludable.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the key characteristics of goods in microeconomics, focusing on two main properties: rivalry and excludability.
2. Step 2: Define rivalry: A good is rivalrous if one person's consumption reduces the amount available for others. Conversely, it is non-rivalrous if one person's consumption does not affect another's ability to consume the same good.
3. Step 3: Define excludability: A good is excludable if it is possible to prevent people who do not pay for it from consuming it. It is non-excludable if it is not possible or very costly to exclude non-payers.
4. Step 4: Recognize that a public good is characterized by being both non-rivalrous and non-excludable, meaning many people can consume it simultaneously without reducing availability, and no one can be easily excluded from using it.
5. Step 5: Compare the options given in the problem to these definitions and identify that the correct characterization of a public good is that it is non-rivalrous and non-excludable.