Final answer:
A marketable permit program corrects externalities by allowing firms to buy and sell permits that give them the right to emit a certain amount of pollution. This system incentivizes firms to reduce pollution efficiently, as permits can be traded based on the relative costs of pollution reduction.
Step-by-step explanation:
A marketable permit program allows firms to buy and sell permits that give them the right to emit a certain amount of pollution. This system helps correct for externalities by incentivizing firms to reduce pollution. Firms that can reduce pollution at a lower cost can sell their excess permits to firms that find it more expensive to reduce pollution. As a result, the total level of pollution is reduced efficiently.
For example, let's say Company A can easily reduce pollution at a low cost, while Company B finds it more expensive to reduce pollution. Company A can sell its extra pollution permits to Company B, allowing Company B to continue its operations without exceeding the pollution limit. This trading of permits helps allocate pollution reduction efforts to the firms that can achieve it at the lowest cost, resulting in a more efficient reduction of externalities.