- Why prices of mangoes, onions, flight tickets and hotel rooms keep changing
- How to read a demand schedule and a supply schedule, and what “market equilibrium” really means
- The everyday factors, besides price, that change how much people buy and sell
- Why governments step into markets, and how price ceilings and price floors work
- What public goods are, and why no private company wants to build them alone
- Why even government intervention can go wrong if it is overdone
market equilibriumsubstitute goodscomplementary goods
price ceilingprice floormonopolypublic goods
free-rider problemhoardingblack marketing
1Demand
Every year, just before the mango season starts, mangoes are costly and people buy very little.
A few weeks later, when the market is full of mangoes, the price drops and people buy much more.
This everyday pattern is what economists call demand.
Demand is the quantity of a product that people are willing and able to buy at a particular
price, depending on their needs, preferences, season, trend and income. Demand is not just wanting
something, it is wanting it and being able to pay for it (purchasing power).
“Willing and able to buy” is the exact phrase examiners look for. Wanting a car you cannot afford
is not demand, it is just a wish.
1.1 The Law of Demand
The Law of Demand states that, other factors remaining constant, when the price of a good
rises, the quantity demanded falls, and when the price falls, the quantity demanded rises. It is an
inverse relationship between price and quantity demanded.
Srivalli buys mangoes through the season. Look at how her buying changes purely because the price
changes, nothing else:
| Price of mango (per kg) | Quantity Srivalli buys |
|---|---|
| ₹150 | 1 kg |
| ₹100 | 2 kg |
| ₹50 | 3 kg |
The quantity of a good that one consumer wants to buy at different prices, keeping other
factors constant, is called individual demand. This table of price and quantity is called a
demand schedule; drawn as a graph, the same information is called a demand curve: it
always slopes downward, because price and quantity demanded move in opposite directions.
1.2 Market demand
Market demand is the total quantity of a good demanded by all buyers in the market at
each price. It is simply the sum of every individual buyer’s demand.
Add two more buyers, Alex and Israt, to Srivalli:
| Price | Srivalli (Q1) | Alex (Q2) | Israt (Q3) | Market demand (Q1+Q2+Q3) |
|---|---|---|---|---|
| ₹150 | 1 kg | 2 kg | 3 kg | 6 kg |
| ₹100 | 2 kg | 4 kg | 6 kg | 12 kg |
| ₹50 | 3 kg | 6 kg | 9 kg | 18 kg |
When the price falls from ₹150 to ₹50, Srivalli alone buys only 2 kg more, but the whole market
buys 12 kg more. Adding up many buyers’ reactions makes the market demand curve flatter and more
responsive to price than any single person’s demand curve.
1.3 Other determinants of demand
A new smartphone model can sell out in hours even though it costs more than the old one. So price
is not the only thing that changes demand. Here is what else does.
Related goods are products whose demand is connected, so a change in the price or
availability of one directly affects the demand for the other. There are two kinds.
Substitute goods
- Can replace each other, like tea and coffee
- If coffee gets costlier, people switch to tea, so tea’s demand rises
- Price of substitute ↑ → demand for the other good ↑
Complementary goods
- Used together, like smartphones and earphones
- If printers sell more, printer cartridges sell more too, even at the same price
- Demand for one ↑ → demand for the other ↑ (and vice versa)
Q. Movie tickets become expensive and fewer people go to the cinema. What happens to the
demand for popcorn sold inside the cinema hall?
Step 1: Movie tickets and cinema popcorn are used together, so they are complementary
goods.
Step 2: Fewer people watching movies means fewer people buying popcorn there.
Answer: Demand for cinema popcorn falls, even though popcorn’s own
price has not changed.
Income
Higher household income makes people feel confident about spending, so demand for many goods
rises even if prices stay the same.
Taste and preference
Srivalli likes mangoes and will not switch to oranges even if oranges are cheaper. Personal taste
overrides price.
Population size and composition
India’s huge population drives its domestic demand. More children means more demand for sports
shoes; more working adults means more demand for formal shoes; more elderly people means more
demand for orthopaedic or comfortable footwear.
Seasonality
Crowded bookshops when a new school session starts, sweet shops during festivals, sweaters in
winter: these shift with the calendar, not with price.
Future price expectations
If people expect a Diwali discount, they delay buying now. If they expect prices to rise soon,
they buy immediately. Either way, demand today changes even though today’s price hasn’t.
The first mango tastes wonderful. The third one, much less exciting. This is because the extra
satisfaction (utility) a person gets from each additional unit of a good keeps falling as they
consume more of it, and this is the diminishing marginal utility principle. As utility from
each extra mango falls, a buyer’s willingness to pay for more mangoes also falls, so demand falls
the more they already have.
2Supply
Supply is the quantity of a product that sellers are willing and able to offer for sale at a
particular price.
The Law of Supply states that, other factors remaining constant, as the price of a good
rises, the quantity supplied rises, and as price falls, the quantity supplied falls. This is a
direct relationship: higher prices mean higher profitability, which pushes producers to
supply more and attracts new sellers into the market.
A mango seller’s own supply schedule shows the same direct relationship:
| Price of mango (per kg) | Quantity seller offers |
|---|---|
| ₹50 | 1 kg |
| ₹100 | 2 kg |
| ₹150 | 3 kg |
Individual supply is the quantity that one particular seller offers at different prices.
Market supply is the sum of the individual supply of every seller in that market.
| Price | Seller A | Seller B | Seller C | Market supply (A+B+C) |
|---|---|---|---|---|
| ₹50 | 1 kg | 3 kg | 2 kg | 6 kg |
| ₹100 | 2 kg | 4 kg | 6 kg | 12 kg |
| ₹150 | 3 kg | 7 kg | 8 kg | 18 kg |
2.1 Other determinants of supply
Price of related goods
The supply of one good depends on how profitable growing or making an alternative good is. A
farmer switches crops if a different crop pays better.
Number of sellers
More sellers competing means market supply can exceed demand, pushing prices down. Fewer sellers
means supply falls short of demand, pushing prices up.
Technology
Better technology lowers the cost of production, so producers can supply more at the same price.
Drip irrigation and weather sensors raise crop output; cold storage lets mango sellers reach
distant markets, raising overall supply.
Future expectations
If sellers expect demand to rise soon, they produce more now. If potato wholesalers expect
prices to rise in the peak season, they may hold back stock now to sell later at a higher price.
3Market Equilibrium
Market equilibrium is the point where the quantity demanded exactly equals the quantity
supplied. There is no excess supply (surplus) and no excess demand (shortage), so there is no
pressure on price to move, and the market is said to be “cleared”.
Look at how the mango market settles at one price:
| Price (₹) | Quantity demanded (kg) | Quantity supplied (kg) | Comparison | Result |
|---|---|---|---|---|
| 40 | 38 | 6 | Qs < Qd | Excess demand (shortage) |
| 100 | 12 | 12 | Qs = Qd | Market equilibrium |
| 150 | 8 | 43 | Qs > Qd | Excess supply (surplus) |
At any price below equilibrium, quantity demanded is more than quantity supplied: there is
a shortage, and price tends to rise. At any price above equilibrium, quantity supplied is more
than quantity demanded: there is a surplus, and price tends to fall. Either way, the market keeps
moving back toward the one price where the two are equal.
3.1 Does market equilibrium exist in the real world?
In theory, equilibrium is simply the price where a demand schedule and a supply schedule match. In
the real world, though, markets rarely stay still long enough to settle there completely.
Students often think equilibrium, once reached, stays fixed forever. It does not. Technology,
wages, interest rates, wars, political events, pandemics, weather and natural disasters constantly
shift demand or supply, so the market is always adjusting toward a new equilibrium rather than
sitting at the old one.
3.2 Case study: hotel tariffs and dynamic pricing
every night, the price changes constantly with demand, season and special occasions. On an
off-season weekday (a Monday in July) a room costs ₹1,500 a night. On a weekend in tourist season
(a Saturday in December) the same room costs ₹8,000 a night. On New Year’s Eve, when demand is at
its peak, it costs ₹25,000 a night. If a group tour suddenly cancels its booking, the hotel may cut
the tariff by 40 per cent overnight just to fill the empty rooms quickly.
- 1 markWhy does the same hotel room cost so differently on a July
Monday and on New Year’s Eve? - 2 marksName three factors, other than the calendar date, that could
make the hotel change its tariff during the day. - 2 marksWhy would the hotel rather cut the price by 40 per cent than
leave the rooms empty?
Revenue is the total amount of money a business earns from selling goods or services (or
from other operating activities), before any expenses are deducted.
A hotel’s tariff also depends on how fast its rooms are getting booked, what nearby hotels are
charging, whether there is a festival, conference or event nearby, the weather forecast, how many days
are left before arrival, and past booking trends. All of this is the market constantly recalculating
where demand and supply currently meet, exactly the way the mango market does, just much faster.
4Role of Government in the Economy
India is the world’s fourth-largest economy, and it runs on a market-based, regulated economy:
prices are mostly set by demand and supply, but the government steps in wherever the market alone
would be unfair or would fail. Markets allocate goods based on who is willing and able to pay,
which is a problem when the good is something everyone needs, like medicine.
4.1 Regulation of unfair practices
Price ceiling
- A maximum price the seller is allowed to charge
- Protects buyers from overcharging
- Example: a capped price on essential medicines
Price floor
- A minimum price a seller must be paid, or a wage a
worker must be paid - Protects sellers/workers from being underpaid
- Example: minimum wage. Must be set above the equilibrium price to actually matter
A price ceiling is a government-imposed price control that sets the maximum amount a
seller can charge for a good or service.
A price floor is a government-imposed limit on how low a price can be charged for a
good, or how low a wage can be paid to a worker. For a price floor to be effective, it must be set
above the market equilibrium price.
A monopoly is a market structure with a single seller or producer controlling the entire
supply of a unique product or service, facing no close substitutes. This gives it the power to charge
higher prices, restrict supply and offer poorer-quality goods or services than a competitive market
would allow, which is why the government regulates such practices.
| Regulator | Sector it watches over |
|---|---|
| Reserve Bank of India (RBI) | Banking |
| Central Consumer Protection Authority | Unfair trade practices and consumer rights violations |
| Telecom Regulatory Authority of India (TRAI) | Telecommunications |
| Securities and Exchange Board of India (SEBI) | Securities market |
What happened: Demand for hand sanitisers surged during COVID-19, causing stockouts.
Some shopkeepers began hoarding and black marketing them.
Government action: Sanitisers were declared essential commodities under the Essential
Commodities Act, 1955, and the maximum retail price for a 200 ml bottle was capped at ₹100.
Result: Many companies started production, and sanitisers soon became widely available at
fair prices.
Hoarding is the accumulation of goods, commodities or money by individuals or firms beyond
what is immediately necessary, typically driven by fear of future shortages, anticipated price
increases, or speculation. Black marketing is the illegal trade of goods and services that are
banned or regulated.
4.2 Provision of public goods
Public goods are goods and services provided by the government for the benefit of all
citizens, for example roads, bridges, public parks and streetlighting, national defence, and
sanitation and drainage systems. Private companies usually do not provide them, because they cannot
earn a direct profit from them.
Suppose a neighbourhood needs a park, and it would cost ₹5,000 per family to build. Even though
every family would benefit, many families think “if others pay, the park gets built anyway, and I
can use it for free.” Because everyone reasons this way, not enough money is collected, and the park
never gets built, even though everyone wanted it. This is exactly why goods that benefit everyone
usually need government funding rather than private or voluntary funding.
4.3 Limitations of government intervention
Government regulation is necessary when markets fail, but too much of it can backfire.
Price distortions
If the government fixes wheat’s maximum price at ₹20/kg while the market would have paid ₹30/kg,
farmers earn less than a free market would give them, and may grow less wheat, causing shortages.
Compliance burdens
Regulations, licences and permits can be a heavy load for small businesses. A small restaurant
may need separate clearances for food safety, fire safety and pollution control before it can even
open, which discourages small entrepreneurs.
Discourages innovation
If price controls mean farmers cannot earn a fair return, they have no reason to invest in
better seeds, irrigation or technology, which hurts long-term productivity.
Ease of doing business means how simple it is to start, run and close a business in a
country, measured by its regulations, bureaucratic efficiency and legal frameworks.
Whose voice should a democratic government listen to when it decides how much to intervene in a
market: consumers, producers, workers, or all three?
the question this chapter leaves you to answer, linking back to how a democratic government is accountable to the people it serves
- Demand is willingness plus the ability (purchasing power) to buy at a given price
- Law of Demand: price and quantity demanded move in opposite directions
- Beyond price, demand shifts with related-goods prices, income, taste, population, season and future price expectations
- Supply is willingness plus ability to sell at a given price; Law of Supply: price and quantity supplied move in the same direction
- Supply shifts with related-goods prices, number of sellers, technology and future expectations
- Market equilibrium: the one price where quantity demanded equals quantity supplied, with no shortage and no surplus
- Real markets rarely stay at one equilibrium; they constantly readjust as conditions change
- Government intervenes through price ceilings, price floors, curbing monopolies and providing public goods
- Public goods struggle to get built through voluntary funding because of the free-rider problem
- Excessive government control can distort prices, burden small businesses and discourage innovation
- 1 markDefine demand.
- 1 markDefine supply.
- 1 markState the Law of Demand in one sentence.
- 1 markState the Law of Supply in one sentence.
- 1 markWhat is market equilibrium?
- 1 markDefine price ceiling.
- 1 markDefine price floor.
- 1 markWhat is a monopoly?
- 3 marksDifferentiate between substitute goods and complementary goods, with one example of each.
- 3 marksList and briefly explain any three factors, other than price, that affect the demand for a good.
- 2 marksWhy does the market demand curve appear flatter (more responsive) than any one buyer’s individual demand curve?
- 3 marksExplain the diminishing marginal utility principle with a suitable example.
- 2 marksHow does an improvement in technology affect market supply? Give one example.
- 3 marks“An increase in income always leads to a rise in demand for all goods.” Defend or refute this statement, giving reasons.
- 3 marksIf the price of petrol doubles, what is likely to happen to (a) the demand for diesel cars, (b) the demand for electric cars, (c) the demand for car accessories, and (d) the demand for public transport?
- 3 marksCategorise the following into substitute goods and complementary goods: (a) movie ticket and popcorn (b) eraser and pencil (c) laptop and computer (d) air conditioner and cooler (e) notebook and pen (f) apple and banana (g) mobile phone and earphones.
- 3 marksExplain, with the help of the “neighbourhood park” example, why public goods are usually not provided by private companies.
- 2 marksWhat is the difference between a price ceiling and a price floor? Give one real-life example of each.
- 5 marksA farmer who traditionally irrigates his fields manually installs drip irrigation, which reduces his water use by 40 per cent and increases his yield by 30 per cent. Explain the effect of this technology upgrade on (a) his cost of production, (b) his willingness to supply mangoes at different prices, and (c) the overall market supply if many farmers adopt this technology.
- 5 marksDuring online festival sales, prices of many products fall sharply. Using the concepts of demand and supply, explain why sellers are willing to sell at such low prices, what happens to market equilibrium when price falls this way, and whether this benefits only consumers or sellers as well.
- 5 marksSuppose the government sets a maximum sale price for an essential vaccine below the market-driven price. Choose the most likely outcome from: (a) surplus (b) shortage (c) no effect (d) fall in demand, and explain your choice using the concept of a price ceiling.
- 5 marksCan excessive government regulation hurt markets? Explain with two suitable examples.
- 5 marksStudy the table below and answer the questions that follow.
Price (₹) 10 20 30 40 50 Quantity demanded (kg) 25 20 15 10 5 Quantity supplied (kg) 5 10 15 20 25 (a) Identify the equilibrium price and equilibrium quantity. (b) What happens in this market if
the price is fixed at ₹20? (c) What happens if the price is fixed at ₹40? - 5 marksThe price of tomatoes in a vegetable market is usually high in the morning and lower by evening. Using demand and supply, explain why this happens, and suggest who is likely to be deciding these prices.
- 1 markWhen the price of a good rises, other factors remaining constant, the quantity demanded generally:
(a) rises(b) falls(c) stays exactly the same(d) becomes zero - 1 markTea and coffee are an example of:
(a) complementary goods(b) substitute goods(c) public goods(d) related but independent goods - 1 markSmartphones and earphones are an example of:
(a) substitute goods(b) complementary goods(c) inferior goods(d) public goods - 1 markAt market equilibrium:
(a) quantity demanded is greater than quantity supplied(b) quantity demanded is less than quantity supplied(c) quantity demanded equals quantity supplied(d) price is always zero - 1 markA minimum wage fixed by the government above the market wage rate is an example of a:
(a) price ceiling(b) price floor(c) subsidy(d) tax - 1 markWhich of the following is NOT a public good?
(a) streetlighting(b) national defence(c) bread sold by a private bakery(d) a public park - 1 markThe Reserve Bank of India (RBI) mainly regulates the:
(a) telecom sector(b) banking sector(c) securities market(d) consumer disputes sector - 1 markThe Law of Supply describes:
(a) an inverse relationship between price and quantity supplied(b) a direct relationship between price and quantity supplied(c) no relationship between price and quantity supplied(d) an inverse relationship between income and supply
Choose: (a) Both A and R are true, and R correctly explains A. (b) Both A and R are true, but R does not correctly explain A. (c) A is true, but R is false. (d) A is false, but R is true.
-
Assertion (A): If the price of coffee rises while the price of tea stays the same, the demand for tea increases.
Reason (R): Tea and coffee are substitute goods, so a rise in the price of one raises the demand for the other. -
Assertion (A): A price ceiling sets the maximum price a seller can charge for a good or service.
Reason (R): The minimum wage fixed by the government is an example of a price ceiling. -
Assertion (A): Public goods like roads and streetlighting are usually built efficiently by private companies because they are highly profitable.
Reason (R): Because everyone can use a public good without paying for it, private companies cannot earn enough direct profit to want to provide it on their own. -
Assertion (A): The government fixes a minimum wage to make sure workers earn enough for their work.
Reason (R): Excessive government regulation can discourage innovation and entrepreneurship.