Public finance

Public finance is the study of how governments manage their monetary resources. It examines the role of government within an economy and how public authorities use money. This field is a major part of political science, political economy, and public economics. Researchers in this field look at government revenue and government expenditure. They study how adjusting these two things can create desirable effects for society.

The purpose of public finance is often viewed as threefold. It focuses on the efficient allocation of available resources. It also looks at the distribution of income among citizens. Finally, it aims to maintain the stability of the entire economy.

Economist Jonathan Gruber provided a framework to help analyze this complex field in 2010. He suggested that we first ask when a government should intervene in the economy. There are two main reasons for this: market failure and the redistribution of income or wealth. Once a decision is made, the government must choose a specific tool. These tools include public provision, taxation, or subsidization.

After choosing a tool, experts study the effects of that intervention on economic outcomes. Finally, researchers use political economy to understand why governments choose specific methods.

In theory, private markets can allocate goods and services efficiently without any waste. This happens when individual tastes match the productive abilities of the economy. However, conditions for market efficiency are often violated. This leads to a situation called market failure. A market failure occurs when private markets do not allocate resources efficiently. One example is a public good, such as national defense. Public goods are non-rival and non-excludable, meaning many people can enjoy them at once. Other causes of market failure include externalities, informational advantages, and network effects.

While governments step in to fix market failures, they can sometimes cause "government failure." This refers to inefficiencies created by government decisions. To avoid this, some theorists suggest a separation of duties. This is known as the Diamond-Mirrlees separation. In this view, programs should be designed to maximize social benefits minus costs. This is called a cost-benefit analysis. The revenue for these programs should then be raised through a taxation system. The goal is to create the fewest possible efficiency losses in economic activity.

History shows that humans have managed public money for thousands of years. In Ancient Greece, governments provided for theaters and art, while also financing wars. The Romans developed a more systemic approach with laws regarding contracts and property. They created a tax system using two types of taxes: tributa and vectigalia. Tributa included land and poll taxes, while vectigalia included inheritance and sales taxes.

These funds supported the military and the cursus publicum, a system of roads. However, the Roman system was regressive, meaning lower-income people often paid higher taxes than the wealthy.

During the 17th and 18th centuries, new economic theories emerged. The laissez-faire approach suggested that governments should have a limited role. In France, the Physiocrats believed the government should mainly guarantee private property. They supported a single tax called the produit net, which was based on a farmer's surplus. Adam Smith also advocated for laissez-faire but believed in a more proactive government. He argued that the state should provide protection, justice, and public works. Smith believed public projects must yield a profit for society that exceeds the benefit to any one individual.

Adam Smith also introduced the Canons of Taxation to guide how governments collect money. He argued that taxation should follow four principles: equality, certainty, convenience, and economy. Following Smith, other economists like Thomas Robert Malthus expanded these ideas. Malthus believed that tax-financed public works were most effective if they increased demand for labor. Eventually, John Ramsay McCulloch helped establish public finance as an independent, well-known field of study.

Modern governments manage money through several specific categories of expenditure. Economists divide these into three main types. The first is government consumption, which is the purchase of goods and services for current use. The second is government investment, which involves spending for future benefits like infrastructure. The third is transfer payments, which are money transfers like social security.

Governments also manage deficits, which occur when spending exceeds revenue. If deficits accumulate over time, they become the total public debt. Deficit finance allows governments to smooth tax burdens over time, but it can also limit the options of future governments.