社会的厚生関数

A social welfare function is a mathematical tool that measures society's overall well-being by aggregating the utilities of all individuals. Economists use it to evaluate whether economic outcomes improve societal welfare and to assess market performance beyond simple equilibrium analysis.

A utilitarian social welfare function adds up the utility of every individual, giving equal weight to each person's utility. It represents total welfare as the sum of all individual utilities, regardless of how that utility is distributed across the population.

Utilitarian social welfare functions focus exclusively on the sum of utilities without accounting for distribution among individuals. This means two outcomes with identical total utility are deemed equally desirable, even if one creates significant inequality, because the framework ignores fairness considerations.

Yes, under utilitarianism, a situation where one person holds most utility while others have very little can still be considered optimal if total welfare is maximized. Redistribution of resources is often ignored unless it increases total welfare, making equity concerns secondary to efficiency.

General equilibrium analysis explores how markets interact and adjust to achieve balance, but equilibrium does not always align with what society considers desirable. Social welfare functions provide the specific standards economists use to evaluate whether market equilibrium outcomes are actually beneficial for society.

Utilitarian welfare functions emphasize efficiency by maximizing total welfare but do not prioritize equity or fairness. Alternative approaches, such as Rawlsian or egalitarian welfare functions, can incorporate fairness considerations and offer a broader perspective on societal well-being beyond pure utility maximization.