Which of the following could lead to a positive externality on the international scale?

• A. A country developing a new vaccine and sharing it globally
• B. A firm dumping waste into a river that flows into neighboring countries
• C. A government subsidizing domestic fossil fuel production
• D. A nation imposing tariffs on imported goods

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the concept of a positive externality. A positive externality occurs when an action by an individual or country results in benefits to others who are not directly involved in the activity.
2. Step 2: Analyze each option to see if it creates benefits beyond the country taking the action. For example, developing a new vaccine and sharing it globally can improve health outcomes worldwide, benefiting other countries.
3. Step 3: Recognize that dumping waste into a river is a negative externality because it harms neighboring countries, not benefits them.
4. Step 4: Understand that subsidizing fossil fuel production typically encourages more pollution and does not create benefits for other countries, so it is not a positive externality.
5. Step 5: Note that imposing tariffs on imports is a protectionist policy that generally restricts trade and does not create external benefits internationally.