Answer: The free market will have difficulty building the levee because the levee is non-rival and non-excludable. So the government may have to intervene and force homeowners to pay through taxes to fund the levee as the benefits exceed the costs.
Step-by-step explanation:
From the question, we are informed that if there are 1000 homes in a flood zone in an area whereby the sea levels are rising and there's an additional 1000 homes that are above the flood zone and are at less risk. Since the levee costs $22,000,000 to build, the best thing to do economic sense will be that the free market will have difficulty building the levee because the levee is non-rival and non-excludable.
It should be noted that in a free market, decisions are made by individuals through price signals and forces of demand and supply. Therefore since this is a public good as it is non rival and non excludeable, there will be need for the intervention of the government in order to collect taxes from the homeowners.