What is the concept called that suggests private individuals can reach an efficient outcome without government involvement when externalities exist, given specific conditions?

Explanation

The Coase theorem states that if property rights are well-defined and transaction costs are low, private parties can negotiate to resolve externalities efficiently without government intervention. Arrow’s impossibility theorem relates to social choice theory, the drop-in-the-bucket problem concerns negligible individual impact, and the free rider dilemma involves individuals benefiting without paying.