Final answer:
Among the given scenarios, Marlo's arrangement to cover part of her neighbor's delivery costs is not a government-imposed corrective tax or subsidy. Taxes on emissions and production practices are government tools to address externalities by incorporating the marginal social cost into production costs, while subsidies, such as covering immunization costs, are used to encourage socially beneficial actions.
Step-by-step explanation:
Corrective taxes and subsidies are economic tools used by governments to address externalities by altering the cost of production for businesses. A tax on polluting goods is an example of a corrective tax, aimed to make the private cost reflect the marginal social cost (MSC), thus guiding firms to a socially optimal level of production. This is done by taxing a good or service to an extent that external costs are internalized in its price. On the other hand, government subsidies support certain actions or products to encourage more of these behaviors or reduce the associated negative externalities. Subsidies increase the supply by reducing the cost of production.
In the scenarios provided, the government charging a tax equal to the difference between the marginal social cost and the marginal private cost of emissions, and imposing a unit tax on paper production to reduce emissions of carcinogenic toxins, are both examples of a corrective tax. However, the particular example where a business owner, Marlo, arranges to cover part of the delivery costs to adjust the timing of a neighbor's deliveries, does not represent a government-imposed corrective tax or subsidy; rather, it's a private agreement to mitigate an externality. Meanwhile, the government covering part of the cost of a particular immunization is an example of a subsidy aimed at increasing the social benefit of widespread vaccination.