Economics / Complete Study Notes

Explain economics through scarcity, choice, resource allocation and human behaviour.

Compare microeconomics and macroeconomics by focus, questions, variables and examples.

Identify positive statements (what is) and normative statements (what ought to be).

Time, money, labour, land, machinery and natural resources are finite.

People have many wants, but cannot satisfy them all at the same time.

Choosing one option means giving up another. This involves opportunity cost.

A student with ₹500 may choose between buying a book, going out for a meal, or saving the money. Economics examines the reasoning behind the choice and its consequences.

• Production: What goods and services are created?
• Consumption: How are goods and services used?
• Exchange: How do people trade?
• Distribution: How are income and output shared?

Resources are scarce while human wants are numerous. Society must choose what to produce, how to produce, and for whom to produce.

It also studies time, incentives, institutions, public policy and well-being.

Which goods and services should be produced, and in what quantities?

Example: Should resources go towards public transport, housing or luxury cars?

Which methods and combinations of resources should be used?

Example: Should a firm use labour-intensive methods or automation?

Who receives the goods and services produced?

Example: How should healthcare, education and other services be distributed?

Different economic systems answer these questions using varying combinations of markets, governments and communities.

• Consumer choice
• Demand for products
• Saving and spending decisions

• Production and costs
• Pricing decisions
• Profit and competition

• Demand and supply
• Market price
• Market structure

How does a rise in the price of coffee affect the quantity of coffee demanded by consumers?

• Why might consumers switch from one brand to another when prices change?
• How does a rise in wages affect a firm’s production costs?
• How does competition influence the price and quality of mobile services?
• How does a tax on a particular product affect buyers and sellers?
• How does a business decide the quantity it should produce?

Consumer, firm, industry or particular market. That is the defining focus of microeconomics.

GDP, economic growth, productivity and aggregate production.

Unemployment, inflation, cost of living and purchasing power.

Fiscal policy, monetary policy, trade, exchange rates and balance of payments.

What explains a rise in India’s overall inflation rate, and what can policymakers do about it?

• What causes an economy’s GDP to grow or contract?
• Why does the general price level rise, and how is inflation measured?
• What factors influence the overall unemployment rate?
• How can government taxation and spending influence economic activity?
• How do interest-rate decisions affect borrowing, investment and aggregate demand?
• How do exchange-rate movements influence imports and exports?

Household consumption and firm investment decisions contribute to aggregate demand, output and employment.

Inflation, interest rates, taxation and economic growth affect household budgets and business plans.

Higher interest rates may reduce a household’s loan demand (micro) and, across the economy, moderate consumption and investment (macro).

• Descriptive and analytical
• Based on observable evidence
• Can be tested against data
• May be supported or contradicted by research

• A rise in the price of a product may reduce quantity demanded, other things equal.
• Higher interest rates can increase the cost of borrowing.
• India’s GDP grew by a measured rate in a given year.

Positive does not mean “good” or “favourable”. It means concerned with what is, was or may be, based on evidence.

• Evaluative and prescriptive
• Reflects values and priorities
• Often uses words such as should, fair, better or desirable
• Cannot be settled by facts alone

• The government should increase spending on public healthcare.
• Income inequality should be reduced.
• Essential food items ought to be made more affordable.

Policy debates involve choices about fairness, priorities and social goals; those choices need normative judgement.

“A higher carbon tax can increase the cost of using fossil fuels and may reduce emissions.”

This is a claim about likely effects that can be studied empirically.

“Therefore, the government should raise the carbon tax to protect the environment.”

This is a recommendation based on environmental and social priorities.

Evidence helps predict consequences, while values help decide which outcomes society prefers.

Studies how scarce resources are allocated among competing uses to satisfy wants.

Micro: individual units and specific markets.

Macro: aggregate performance of the economy.

Positive: what is / what can be tested.

Normative: what ought to be / value judgement.

When a small price change causes a large change in quantity demanded, demand is elastic.

When quantity demanded changes only slightly despite a price change, demand is inelastic.

A 10% rise in price may reduce demand by 20% for one product but by only 2% for another. The first product has more price-responsive demand.

PED = % change in quantity demanded ÷ % change in price

Quantity demanded changes by a greater percentage than price.

Quantity demanded changes by the same percentage as price.

Quantity demanded changes by a smaller percentage than price.

Price and quantity demanded usually move in opposite directions. For classifying the degree of elasticity, economists generally use the absolute value of PED.

More close substitutes generally make demand more elastic.

When a product’s price rises, consumers can switch to similar alternatives. The easier this is, the larger the fall in demand for the original product. Fewer suitable alternatives mean less price-responsive demand.

If the price of Pepsi rises, buyers may switch to Coca-Cola or another soft drink. A patient may have fewer options if a prescribed medicine has no suitable substitute.

More substitutes → more elastic demand.

Demand for necessities is usually less elastic than demand for luxuries.

Necessities satisfy basic needs, so people may keep purchasing them even after prices rise. Luxury purchases can be more easily reduced, replaced or postponed.

A family may continue purchasing rice after a price increase, but it may postpone a designer handbag or luxury watch when its price rises.

Necessities → less elastic; luxuries → more elastic.

The larger the share of income spent on a product, the more carefully consumers tend to respond to its price.

A small increase in a cheap item may scarcely affect the budget, but the same percentage increase in an expensive item adds significant expenditure and may encourage comparing alternatives or delaying the purchase.

Salt rising from ₹25 to ₹30 may barely affect buying decisions. A refrigerator becoming ₹6,000 more expensive may cause a buyer to wait or choose another model.

Higher budget share → usually more elastic demand.

Demand is generally more inelastic in the short run and more elastic in the long run.

Consumers cannot immediately change habits, equipment or travel arrangements. Given more time, they can look for substitutes, adopt technology and change routines.

After petrol prices rise, a driver may initially continue driving. Later, they may use public transport, carpool or consider an electric vehicle.

More time to adjust → more elastic demand.

Products whose purchase can be delayed generally have more elastic demand.

When purchase is not urgent, consumers can wait for a discount, save money or reconsider whether it is needed. Urgent or essential consumption is more difficult to postpone.

Someone may postpone buying a television when its price rises. Emergency medical treatment generally cannot be delayed simply because it becomes more expensive.

Can postpone → more elastic; cannot postpone → less elastic.

A commodity with several uses may have more elastic demand.

Consumers can cut the less-essential uses when price rises while retaining important uses, reducing overall consumption. A product with only one essential use gives less scope to adjust.

If electricity prices rise, a household may reduce air-conditioning, water heating and unnecessary lighting, while keeping electricity for essential needs.

More uses → more ways to reduce consumption.

Strong habits can make demand less responsive to price changes, especially in the short run.

A habitual consumer may struggle to reduce consumption right after a price rise. With time, they may alter habits or find substitutes, increasing responsiveness.

After cigarette prices rise because of taxes, a habitual smoker may not immediately reduce consumption, although higher prices may encourage reduction or quitting over time.

Stronger habits → often less elastic demand.

Demand for a narrowly defined product is generally more elastic than demand for a broad product category.

A narrow product definition leaves many alternative products within the wider category. For a broadly defined market, fewer substitutes exist outside the entire category.

A higher price for one cola brand lets buyers switch brands. If all beverage prices rise, alternatives are more limited than for a single cola brand.

Narrow market → more elastic; broad market → less elastic.

The absolute cost of a purchase can influence how carefully consumers react to a price change.

A small absolute price increase on a low-cost item may not be worth changing buying behaviour for. A noticeable increase on an expensive product may prompt research or delay. This is a general tendency, not a universal rule.

A buyer may continue buying a pencil after a small rise in price, but may compare brands or wait for a sale when a laptop becomes ₹12,000 more expensive.

Expensive purchases often prompt more comparison and delay.

Price elasticity depends on how easily consumers can adjust their choices when prices change.

Look at substitutes, necessity, income share, adjustment time, postponement, number of uses, habits, market definition and price level to understand price responsiveness.

Scope of Economics — 16 pages

Price Elasticity of Demand — 14 pages