Public finance

Public finance is the study of the role of the government in the economy. It is the branch of economics which the government revenue and government expenditure of the public authorities and the adjustment of one or the other to achieve desirable effects and avoid undesirable ones.

The purview of public finance is considered to be threefold: governmental effects on (1) efficient allocation of resources, (2) distribution of income, and (3) macroeconomic stabilization.

The proper role of government provides a starting point for the analysis of public finance. In theory, under certain circumstances, private markets will allocate goods and services among individuals efficiently (in the sense that no waste occurs and that individual tastes are matching with the economy's productive abilities). If private markets were able to provide efficient outcomes and if the distribution of income were socially acceptable, then there would be little or no scope for government. In many cases, however, conditions for private market efficiency are violated. For example, if many people can enjoy the same good at the same time (non-rival, non-excludable consumption), then private markets may supply too little of that good. National defense is one example of non-rival consumption, or of a public good.

"Market failure" occurs when private markets do not allocate goods or services efficiently. The existence of market failure provides an efficiency-based rationale for collective or governmental provision of goods and services.Externalities, public goods, informational advantages, strong economies of scale, and network effects can cause market failures. Public provision via a government or a voluntary association, however, is subject to other inefficiencies, termed "government failure."

Under broad assumptions, government decisions about the efficient scope and level of activities can be efficiently separated from decisions about the design of taxation systems (Diamond-Mirlees separation). In this view, public sector programs should be designed to maximize social benefits minus costs (cost-benefit analysis), and then revenues needed to pay for those expenditures should be raised through a taxation system that creates the fewest efficiency losses caused by distortion of economic activity as possible. In practice, government budgeting or public budgeting is substantially more complicated and often results in inefficient practices.

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