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Public economics

Public economics is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Public economics rather than just read about it. In short: Public economics (or economics of the public sector) is the study of government policy through the lens of economic efficiency and equity. Public economics builds on the theory of welfare economics and is ultimately used as a tool to improve social welfare.

Public economics — main illustration
Public economics — illustration

Key takeaways

  • Public economics belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Public economics to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Public economics from memory before moving on to harder problems.

Reference excerpt

Public economics (or economics of the public sector) is the study of government policy through the lens of economic efficiency and equity. Public economics builds on the theory of welfare economics and is ultimately used as a tool to improve social welfare. Welfare can be defined in terms of well-being, prosperity, and overall state of being. Public economics provides a framework for thinking about whether or not the government should participate in economic markets and if so to what extent it should do so. Microeconomic theory is utilized to assess whether the private market is likely to provide efficient outcomes in the absence of governmental interference; this study involves the analysis of government taxation and expenditures. This subject encompasses a host of topics notably market failures such as, public goods, externalities and Imperfect Competition, and the creation and implementation of government policy. Broad methods and topics include:

the theory and application of public finance Analysis and design of public policy distributional effects of taxation and government expenditures analysis of market failure and government failure. Emphasis is on analytical and scientific methods and normative-ethical analysis, as distinguished from ideology. Examples of topics covered are tax incidence, optimal taxation, and the theory of public goods.

Subject range The Journal of Economic Literature (JEL) classification codes are one way categorizing the range of economics subjects. There, Public Economics, one of 19 primary classifications, has 8 categories. They are listed below with JEL-code links to corresponding available article-preview links of The New Palgrave Dictionary of Economics Online (2008) and with similar footnote links for each respective subcategory if available:

JEL: H (all) – Public Economics JEL: H0 – General JEL: H1 – Structure and Scope of Government JEL: H2 – Taxation, Subsidies, and Revenue JEL: H3 – Fiscal Policies and Behavior of Economic Agents JEL: H4 – Publicly Provided Goods JEL: H5 – National Government Expenditures and Related Policies JEL: H6 – National Budget, Deficit, and Debt JEL: H7 – State and Local Government; Intergovernmental Relations JEL: H8 – Miscellaneous Issues.

Market failures

The role of government in providing efficient and equitable markets is largely underpinned by addressing market failures that may arise. Public Economics focuses on when and to what degree the government should intervene in the economy to address market failures. Some examples of government intervention are providing pure public goods such as defense, regulating negative externalities such as pollution and addressing imperfect market conditions such as asymmetric information.

Public goods Pure public goods, or collective consumption goods, exhibit two properties; non-rivalry and non-excludability. Something is non-rivaled if one person's consumption of it does not deprive another person, (to a point) a firework display is non-rivaled - since one person watching a firework display does not prevent another person from doing so. Something is non-excludable if its use cannot be limited to a certain group of people. Again, since one cannot prevent people from viewing a firework display it is non-excludable. Due to these constraints, one of few examples of a "pure public good" is national defense - it is both non-rivalry and non-excludable. Another example, of a pure public good is knowledge. Consider a book. The book itself can be destroyed and thus is excludable. However, the knowledge obtained from the book is far more difficult to destroy and is non-rivalrous and non-excludable. In reality, not all public goods can be classed as 'pure' and most display some degree of excludability and rivalrous. These are known as Impure public goods. To visualize the public good's characteristic of non-excludability, it would be the inability to build a fence, barrier or wall that would block the good from consumption. In the modern era, digital replication allows several goods to be non-rivalry; since, people from all over the world can access it if you have access to the internet and a device. Due to the two unique properties that public goods exhibit, being non-rivalrous & non-excludable, it is unlikely that without intervention markets will produce the efficient amount. It therefore, the role of government to regulate the production of public goods so as to create an efficient market equilibrium.

Externalities Externalities arise when consumption by individuals or production by firms affect the utility or production function of other individuals or firms. Positive externalities are education, public health and others while examples of negative externalities are air pollution, noise pollution, non-vaccination and more. Pigou describes as positive externalities, examples such as resources invested in private parks that improve the surrounding air, and scientific research from which discoveries of high practical utility often grow. Alternatively, he describes negative externalities, such as the factory that destroys a great part of the amenities of neighboring sites. The role of government is to address the negative external effects and societal deadweight loss created from inefficient markets

Imperfect competition Imperfect competition within markets can take many forms and will often depend on the barriers to entry, firms profit and production objectives and the nature of the product and respective market. Imperfect competition will lead to a social cost and it is the role of government to minimize this cost. Some notable imperfections include:

Companies sell differentiated products There are barriers to exit and entry Suboptimal output and pricing In its essence, the role of government is to address the issues that arise from these market failures and decide the optimal degree of intervention necessary.

Taxation

… excerpt ends here. Continue reading the full article.

Illustrations

Public economics: A.C. Pigou (1877-1959).
A.C. Pigou (1877-1959).
Public economics: Jules Dupuit (1804-1866).
Jules Dupuit (1804-1866).

Worked examples

Example 1 — a first encounter with Public economics

Start with the simplest possible case. Write down what Public economics claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Public economics before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Public economics ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Public economics

In research
Public economics appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Public economics in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Public economics is common in secondary-school and first-year university syllabi. It links to neighbouring topics Public economics, so understanding it makes those chapters shorter.
In everyday life
Look for Public economics outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Public economics in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Public economics means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Public economics out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Public economics in simple terms?

Public economics (or economics of the public sector) is the study of government policy through the lens of economic efficiency and equity. Public economics builds on the theory of welfare economics and is ultimately used as a tool to improve social welfare.

Why does Public economics matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Public economics?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Public economics.

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