Basic Concepts and Economic Systems

Every society has the same basic problem: people want far more than the resources can produce. Land, labour, capital and time are limited, while human wants are unlimited. This gap is called scarcity, and economics is the study of how we choose when we cannot have everything. If resources were unlimited, there would be no economics at all.

Because of scarcity, every society must answer three central problems: (1) What to produce and in what quantity, (2) How to produce (which technique, labour-heavy or machine-heavy), and (3) For whom to produce (how output is shared among people). Every economic system, whether capitalist, socialist or mixed, is simply a different way of answering these three questions.

Opportunity cost is the value of the next best alternative you give up when you make a choice. It is not the money you spend, but what you sacrifice. If Radhika spends Saturday evening studying for an exam instead of going to a film, the film is her opportunity cost. For a farmer who grows wheat on a plot, the best alternative crop he could have grown is the opportunity cost.

Production Possibility Frontier (PPF) is the curve that shows the maximum combinations of two goods an economy can produce with its given resources and technology. It is drawn concave (bowed outwards) because as we shift resources from one good to the other, the opportunity cost keeps rising. A point on the curve means full use of resources, a point inside means unemployment or waste, and a point outside is not possible today. Economic growth or better technology shifts the whole curve outwards.

An economic system is the framework a country uses to answer the three central problems: what, how and for whom to produce. The main difference between systems is who owns the resources (private individuals or the state) and who takes the decisions (the market or the planners).

Think of the three systems as points on a line. At one end is a pure market economy (Adam Smith's laissez-faire: the state keeps out of business); at the other end is a pure command economy (the state decides everything). Almost no country sits at either end today. Even the USA regulates markets, and even China allows private enterprise. Nearly every real economy is mixed, only in different proportions.

India's choice was deliberate. After 1947 the leaders wanted rapid industrial growth and social justice. Nehru rejected the Soviet model because it meant the state owning all factories and farms; he also did not want unregulated capitalism. So India kept private property and democracy but gave the public sector the commanding heights (steel, heavy machinery, power, railways), and started Five-Year Plans in 1951 under the Planning Commission. The word Socialist was added to the Preamble by the 42nd Amendment (1976). From 1991 the role of the market was widened, but the mixed character remains.

To study a whole economy, economists group its activities into sectors by what the activity does to a product. Think of a loaf of bread: the farmer grows wheat (take from nature), the mill makes flour and the bakery bakes bread (change the material), and the shop sells it to you (deliver it). Each stage belongs to a different sector.

Economists Colin Clark and A. G. B. Fisher noticed a pattern called the Clark-Fisher thesis: as a country develops, the share of the primary sector in output and jobs falls, the secondary sector rises first, and finally the tertiary sector becomes the largest. India has jumped quickly to services: the service sector is now the largest contributor to GDP (more than half of GVA), while agriculture and allied activities contribute only a small share of GDP but still employ a very large part of the workforce. This mismatch between share in output and share in jobs is a basic feature of the Indian economy.

Economists sort goods in several ways, and each way answers a different question. By use: is it bought to be consumed or to produce more? By stage: is it finished or still going into something else? By access: can others be stopped from using it, and does my use reduce yours? By demand behaviour: what happens to demand when income changes?

A public good has two features. Non-rivalry: one person's use does not reduce what is left for others. Non-excludability: no one can be stopped from enjoying it, even if they do not pay. Because people can enjoy it without paying (the free-rider problem), private firms will not supply it, so the government provides it and pays through taxes. A shirt or a pizza is not a public good, since it can be sold to one buyer only.

Two more groups are asked often. Merit goods are goods society thinks everyone should have, even if people would not buy enough on their own, such as education, vaccination and subsidised food; the state subsidises them. Demerit goods are harmful goods like tobacco and alcohol; the state discourages them through high taxes (called sin taxes). Free goods (like air) have no price because they are not scarce, while economic goods are scarce and have a price. Services are intangible: they cannot be stored or touched, and are produced and consumed at the same time.

Economics has its own family tree. Knowing who said what, and in which book, is a favourite one-mark area for SSC and Railway exams. Read the table below as a story: Smith started the subject, Malthus and Ricardo argued over population and rent, Marx attacked the system, Marshall polished the tools, and Keynes rescued the world from the Great Depression by arguing that the state must spend.

Before the big macro chapters begin, a handful of working terms must be clear. Most mistakes in economics questions come from mixing up stock and flow, saving and investment, or wealth and income. Get these right and later chapters become easy.

This is the circular flow of income in a simple two-sector economy (households and firms). Whatever households earn flows back as spending, so income = output = expenditure. Three things drain money out of the circle, called leakages: saving, taxes and imports. Three things pour it back in, called injections: investment, government spending and exports. An economy is stable when leakages equal injections.