A possible positive externality to this idea would be that the money that businesses gain in trading their unused amount under the restrictions stimulates economic activity. Also the businesses that are buying the extra amount that they can pollute will probably attempt to pollute less so that they do not have to become dependent on other companies to prevent going over the “cap.” A possible negative externality would be that a company’s cost to produce would go up because they would have to spend money on making things with less pollution. This may cause a decrease in supply in that certain good. This would affect the consumer because with a lower supply the price would most likely go up.
This is a government solution to the problem because the government is the entity that is setting the “cap” on how much emissions and pollution can occur. This is not set by other businesses so it makes it a government solution. Also the government will tax those who go above the set limit and if it was a private solution a tax would not be able to be involved as a consequence. It is also not private because through the trading part of the idea, businesses can trade the any amount of pollution that was below their set goal and this was created as an incentive by the government so that businesses would compete in lowering their pollution levels at a