Libertarianism is rooted in the principle of self-ownership and entitlement theory. It argues that if income is acquired through just means (fair exchange or labor), the state has no moral authority to redistribute that wealth, as it violates individual property rights. Other philosophies like utilitarianism may justify redistribution to increase aggregate social welfare.

Comparing the effectiveness of resource allocations often involves interpersonal utility comparisons. Because utility is subjective and cannot be measured on a universal scale, economists cannot objectively determine if one person's gain outweighs another's loss without making arbitrary value judgments. This limitation makes it difficult to rank different social states or allocations purely on economic grounds without a defined social welfare function.

Rawls's maximin principle focuses on improving the welfare of the least advantaged. He argues that some income inequality is acceptable if it provides the necessary incentives for productivity and innovation. If total societal output increases due to these incentives, the absolute position of the poorest can be improved more than it would be under a perfectly equal but stagnant distribution.

Rawls's 'Difference Principle' posits that social and economic inequalities are only justified if they result in compensating benefits for the least advantaged members of society. Consequently, the government should prioritize policies that maximize the welfare of the worst-off, as this is the most equitable way to structure a society under the 'veil of ignorance'.

Societal marketing is a philosophy that holds that a company should make marketing decisions by considering consumers' wants, the company's requirements, and society's long-term interests. It moves beyond simple profit maximization to incorporate ethical and social responsibilities, ensuring that business growth does not come at the expense of the general population's well-being or future sustainability.

Utilitarianism generally supports redistribution to maximize total utility, often assuming diminishing marginal utility of income. Liberalism (in the Rawlsian sense) supports redistribution to protect the least advantaged. Libertarianism emphasizes property rights and individual liberty, typically opposing mandatory redistribution. The provided answer key 'D' appears to contain formatting errors and potentially conflates the order, but is preserved per instructions.

An individual who benefits from a service without contributing to its cost is known as a free rider. In the case of public broadcasting, because the signal is available to anyone with a receiver (non-excludable), those who avoid paying the license fee while still watching the content are classic examples of free riders, which can undermine the funding model of such services.

The socially optimal level of a public good is achieved when the sum of the marginal benefits to all individuals in society equals the marginal cost of producing that good. This condition ensures that the last unit produced provides a benefit exactly equal to the cost of its production, maximizing net social welfare.

Positive externalities occur when the social benefit of a good exceeds the private benefit, leading to under-provision by the market. Similarly, public goods are non-excludable and non-rival, which leads to the free-rider problem and subsequent under-provision. Both scenarios represent market failures where the market mechanism fails to allocate resources efficiently without some form of intervention.

Public goods are defined by two key properties: non-excludability and non-rivalry. Non-excludability means it is impossible or prohibitively expensive to prevent individuals from using the good once it is provided. Non-rivalry implies that one person's consumption of the good does not diminish the amount available for others. Environmental resources like clean air often exhibit these traits, leading to potential market failures.