The Price Puzzle: What Drives the Market: Class 9 Social Science · Chapter 9

A plate of pani puri costs ₹30 at the stall outside your school and ₹80 at a mall food court. An auto ride that costs ₹60 on a dry afternoon can cost ₹100 in a cloudburst, if you can find an auto at all. A tatkal train ticket costs more than one booked weeks ahead, and woollen jackets often go on sale in February. No official announces these prices. So where do they come from?

Back in Grade 7, in ‘Understanding Markets’, you watched buyers and sellers haggle and saw that a price pitched too high or too low does not last. This chapter looks under the price tag. Two forces are at work on every price, from a movie ticket to a kilo of onions: demand (माँग), what buyers want and can pay for, and supply (पूर्ति), what sellers are ready to offer. You will see how the two meet to settle a price, why that price keeps moving in real life, and when the government steps in.

9.1 Demand

Lots of people would love a new laptop, a sports bike or a flat by the sea. Wanting is easy. In economics, a wish counts as demand only when the person is also willing and able to pay for the thing at its price. The money a buyer can command matters, and so does what that money will fetch. Economists call this purchasing power (क्रय शक्ति): how much a given sum of money will fetch at a given moment. When prices rise faster than incomes, purchasing power shrinks.

Demand always comes with a price attached. Ask how many kilograms of grapes a family will buy, and the honest answer is “That depends on the price.” At ₹160 per kg they might buy half a kilo as a treat; at ₹40 per kg, three kilos. More is bought when the price falls and less when it rises. The pattern is so common that economists call it the law of demand (माँग का नियम).

9.1.1 Individual demand: schedule and curve

Let us follow one buyer. Tenzin buys grapes for his family from a fruit cart near his home in Siliguri. Through the season the price per kilogram changes, and so does the amount he buys each week. The quantity one buyer wants at each price, with his income, tastes and other prices held steady, is his individual demand. Written as a table, it becomes a demand schedule (Table 9.1).

Now draw it. Put price on the vertical axis and quantity on the horizontal axis, mark one point for each row and join the points. The line you get is Tenzin's demand curve (Fig. 9.1). It slopes down from left to right, and that slope is the law of demand in picture form: moving down to lower prices, you move right to larger quantities.

9.1.2 Market demand

A fruit seller cares about more than one buyer. She cares about everyone who passes her cart. Market demand is the total quantity that all the buyers in a market want at each price. To find it, take one price at a time and add up what every buyer would buy at that price.

Suppose Tenzin's neighbours Farhan and Gurleen buy from the same cart. Their weekly plans are in Table 9.2. Look at Gurleen: at ₹160 she buys none at all, because grapes are not worth that much to her.

Adding sideways like this, price by price, is why market demand is called a horizontal sum of individual demands. Plot the totals and you get the market demand curve (Fig. 9.2). It also slopes downward, for two reasons: each buyer buys more at lower prices, and some buyers, like Gurleen, join the market only when the price is low enough.

9.1.3 Other determinants of demand

Price is not the only thing that moves demand. On the eve of a cricket final with India playing, shops sell out of team jerseys though their price has not changed at all. Something other than price, here excitement, has made people want more. Such forces are called the determinants of demand. Six of them matter most.

Prices of related goods

What happens to bus rides when a city's metro fare jumps? Nothing about the bus has changed, yet buses fill up. Commuters weigh the two options again, and for some the slower but now relatively cheaper bus wins. Goods that can stand in for each other like this are substitute goods (स्थानापन्न वस्तुएँ); mustard oil and groundnut oil are another pair. A price rise for one raises the demand for the other.

Other goods only make sense as a team: a scooter and a helmet, a gas stove and an LPG cylinder, a cricket bat and a ball. These are complementary goods (पूरक वस्तुएँ). Their demands rise and fall together, so a price rise for one lowers the demand for its partner. Helmet shops feel it when scooters get dearer: fewer new scooters on the road means fewer new riders shopping for helmets.

Income of the buyer

A pay rise changes a family's shopping list. Fruit, new clothes and a holiday move up the list, so for most goods demand grows with income. But not for all. A family that used to squeeze into shared autos may buy its own scooter once its income grows, and then it takes fewer shared-auto rides. Goods that people buy less of as they grow richer are called inferior goods. The word describes how buyers behave, not the quality of the good. For a few basics, such as salt, demand hardly changes with income at all.

Tastes and preferences

One cricket fan will pay almost anything for a ticket to the final; her brother would not go if the ticket were free. What people like decides what they demand, and likes also change across a whole society. Interest in fitness has pushed up the demand for running shoes and gym memberships. The United Nations declared 2023 the International Year of Millets, and food companies answered the new interest with millet biscuits, noodles and snacks.

Size and make-up of the population

The more people there are, the more of almost everything they demand. United Nations estimates show that India became the world's most populous country in 2023, so the spending of Indian households is a big force in the economy. Who those people are matters too. A hill town where many retired people live keeps its chemists and eye clinics busy; a new township of young families wants school vans and tiffin boxes; a city that draws young workers runs short of rented rooms.

Seasons and festivals

Demand also follows the calendar. Raincoats and umbrellas sell fast in the monsoon, kites fill the shops before Makar Sankranti, and colours and water guns before Holi. Air coolers are wanted in May, not in December. In each case the price may not have moved at all; the season or the festival has.

Expected future prices

Rumours travel fast in markets. A news report that onions may double in price next month sends families to fill an extra bag today. Word that a new phone model launches soon makes buyers hold off, since the current model will then get cheaper. Today's price is the same in both stories; only expectations about tomorrow differ, and they push today's demand up in the first case and down in the second.

9.2 Supply

Now cross to the other side of the counter. The grape growers around Nashik, the traders at the wholesale mandi and the cart sellers in your street are all suppliers. Supply is about what sellers are ready to offer, and like demand it is always tied to a price.

Sellers react to price the opposite way from buyers. A higher price makes each kilo more profitable, so a grower picks and sends more and a trader stays open longer. A very high price even pulls in new sellers: a vegetable vendor may add grapes to her cart. A low price does the reverse. This gives the law of supply (पूर्ति का नियम).

9.2.1 Individual and market supply

Seen from a farm, a grape season goes like this. In the first weeks only a few vines are ripe, little fruit reaches the market, and traders pay well for it. A few weeks later every vine in the district is heavy with fruit, the mandi is flooded and the price slides. When sellers bring less than buyers want, prices climb; when they bring more, prices sink. Hold on to that idea: it is the key to Section 9.3.

Rukmini, Joseph and Harjeet grow grapes and send them to a town market. Individual supply is what one seller offers at each price. Market supply is the total that all sellers offer at each price, found by adding across, just as we did for demand (Table 9.3).

Harjeet's farm is far from town, so at ₹40 per kg the trip is not worth it and he sends nothing. As the price rises, every grower offers more. Plot the rows and the curves slope upward (Fig. 9.6).

9.2.2 Other determinants of supply

As with demand, many things besides the good's own price change how much sellers offer.

Prices of related goods

A producer's land, machines and working hours can usually make more than one thing. A baker's oven can bake bread or cakes. If wedding-season orders push up the price of cakes while bread sells for the same, the baker gives more oven hours to cakes, and less bread reaches the shops (Fig. 9.7). Farmers make the same kind of choice every season when they decide which crop to sow on a field.

Number of sellers

More sellers mean more supply. When a new wholesale market opens, or many farmers take up a crop, more of it reaches buyers at every price, and the price tends to fall. When sellers leave, say because small shops close after a flood, supply shrinks and the price tends to rise.

Technology and costs

Better technology lets a producer make more from the same effort, which cuts the cost of each unit. A weaver who moves from a handloom to a power loom can make several times as much cloth in a day, and a seed drill lets a farmer sow in a day what once took a week. Cheaper inputs work the same way, while dearer inputs, such as costlier fertiliser or diesel, push supply down (Fig. 9.8).

Expectations about the future

Sellers also act on what they expect. A cement company that expects a building boom next year may set up a new plant, so supply grows later. A trader who expects jaggery to fetch more just before the festival season may keep part of his stock in the godown for now, so today's supply falls. When storing goes far beyond normal needs, mainly to profit from a coming shortage, it is called hoarding; Section 9.4.1 shows how the law deals with it.

9.3 Market equilibrium

Think of a market as a tug-of-war. On one rope are buyers, hoping to pay little; on the other, sellers, hoping to get a lot. Neither team can declare the price on its own. The rope stops moving only where the two teams' plans match.

Picture the whole grape market of a town on a Sunday, with hundreds of buyers and dozens of sellers. Table 9.4 shows how much all of them together want to buy and to sell at five possible prices.

At ₹100, sellers bring 200 kg but buyers want only 100 kg. Quantity supplied is greater than quantity demanded: this is excess supply, or a surplus (अधिपूर्ति). Sellers stuck with grapes that will spoil start cutting their prices, and the price slides down.

At ₹60 the problem is reversed. Buyers want 180 kg but only 80 kg arrive. This is excess demand, or a shortage (अधिमाँग). Some buyers leave empty-handed, others offer more, and sellers notice that they can ask a higher price. The price climbs.

Only at ₹80 do the plans match: buyers want 140 kg and sellers offer 140 kg. Nothing pushes the price up or down. This is the market equilibrium (बाज़ार संतुलन); ₹80 is the equilibrium price and 140 kg the equilibrium quantity. Economists say the market clears: no grapes are left unsold, and no buyer willing to pay ₹80 goes home without them.

On a graph, the equilibrium is the point where the demand curve and the supply curve cross (Fig. 9.9). Any other price leaves a gap between the curves, and that gap is what drives the price back.

Try it yourself in the explorer below. Set a price and read the gap, then press the button and let the market adjust. Next, add an event such as a hailstorm on the vineyards and watch the equilibrium itself move.

9.3.1 Does market equilibrium exist in the real world?

Tomatoes show the answer almost every year. Tomato prices in India usually rise in the lean months of July and August, when heat and heavy rain hurt the crop and its transport. In 2023 the jump was unusually sharp: on 19 July 2023, the all-India average retail price was about ₹119 per kg, according to the Department of Consumer Affairs. Supply had shifted left, so the equilibrium had moved to a much higher price (Fig. 9.11).

The government stepped in for a while. Two cooperative agencies, NCCF and NAFED, bought tomatoes from mandis in Andhra Pradesh, Karnataka and Maharashtra and sold them cheaply in cities where prices had risen most: at ₹90 per kg at first, then ₹80 and ₹70. By 20 August 2023 the Department reported a steady fall in wholesale and retail prices, and the agencies' rate was down to ₹40. Each new harvest, and each spell of bad weather, sets a new equilibrium.

What is true of tomatoes is true of most goods. A weak monsoon, a new highway, a strike at a port, a viral video, a jump in diesel prices or a pandemic can each shift demand or supply. The point where the curves cross is therefore a moving target, more like a fielder chasing a ball that keeps being hit again than a parked car. The neat point on the graph is still useful: it tells you which way the price is being pulled right now.

9.4 Role of government in the economy

India runs mostly on markets: most prices are set by demand and supply, not by an official. Your textbook describes India as the world's fourth-largest economy. Such rankings shift from year to year with growth and exchange rates, but India is clearly one of the biggest. It is not a free-for-all, though. India is a market economy with rules, and the government takes part in it.

Why should a government interfere at all? A market is very good at one job: getting goods to the people who will pay for them. But it has no heart. It sells the last vial of insulin to the highest bidder, not to the sickest patient. For luxuries that is fine; for essentials it can be cruel. So governments also care about equity, a fair deal for low-income and vulnerable families, and step in where the market alone would leave them out.

Governments take part in three main ways, which the rest of this section explores. They regulate unfair practices (Section 9.4.1), they provide public goods that markets neglect (Section 9.4.2), and they must also know where to stop (Section 9.4.3).

9.4.1 Regulation of unfair practices

One tool is a price ceiling (उच्चतम निर्धारित कीमत): a legal maximum price. The fare chart inside many auto-rickshaws is one, fixed by the state transport authority. Another is set by India's National Pharmaceutical Pricing Authority (NPPA), which fixes ceiling prices for essential medicines so that patients are not overcharged.

The opposite tool is a price floor (निम्नतम निर्धारित कीमत): a legal minimum price. The best-known floor is the minimum wage. Central and state governments fix the lowest daily or monthly pay that employers must give workers, so that hard work is not bought too cheaply. The minimum support price (MSP) announced for crops such as wheat and paddy works in a similar spirit: in many states government agencies buy at that price, so farmers who can sell to them need not accept less.

See what each tool does to a market (Fig. 9.12). A ceiling bites only when it is set below the equilibrium price: buyers then want more than sellers offer, and a shortage appears. A floor bites only when it is set above equilibrium: sellers then offer more than buyers want, a surplus. With wages, that surplus would mean more people looking for work than there are jobs, though economists still debate how large this effect is in real labour markets. A ceiling set above the equilibrium price changes nothing at all.

A third worry is monopoly (एकाधिकार): a market with a single seller of something that has no close substitute. With no rival to undercut it, a monopolist can charge more, sell less and let quality slip. Some services are natural monopolies; a city usually has just one company running its electricity wires. That is why State Electricity Regulatory Commissions approve the tariffs that power companies charge, and why the Competition Commission of India investigates firms that misuse a dominant position or fix prices together.

Many markets also have a specialist watchdog, or regulator, that writes rules for the sector and checks that firms follow them (Table 9.5). You may remember some of them from Grade 7.

9.4.2 Provision of public goods

Some things are useful to everyone but hard to sell one by one. Once a streetlight is switched on, everyone walking down the lane gets its light, whether they paid or not, and one more walker does not make it any dimmer. Goods like this are public goods (सार्वजनिक वस्तुएँ). Lighthouses, flood embankments, streetlights, public parks, the police and the army are examples, and governments provide or pay for them.

Why doesn't a private company build them and charge for them? Imagine that the 20 homes in a lane need streetlights costing ₹60,000, or ₹3,000 per home (Fig. 9.13). Each family quietly hopes the neighbours will chip in, so that it can enjoy the light without spending anything. If only 7 families pay, the fund reaches just ₹21,000 and the lane stays dark, though every family wanted light. People who enjoy a good without paying for it are called free riders. Because of them, no firm can collect enough to cover the cost, so the government provides such goods and pays for them from taxes that everyone shares.

9.4.3 Limitations of government intervention

Government action can fix some failures of the market, but it has costs of its own. Too much of it, or the wrong kind, can hurt the people it means to help. Three problems come up again and again.

Prices that send the wrong signal. Suppose a town caps the price of milk at ₹45 a litre when the market price is ₹56. Families are pleased at first. But dairy farmers now get less for each litre than buyers would gladly pay, so some sell their milk to sweet shops in the next town and some keep fewer cows. Less milk reaches the town, queues form and some families end up with none. A price set below equilibrium weakens the very reward that brings supply to market.

Paperwork that weighs on small firms. Imagine Meenakshi, who wants to open a two-person carpentry workshop. A big company has an office to handle forms; she has a notebook. Registering the shop, getting a trade licence from the municipality, signing up for tax and getting approval for a bigger electricity connection for her machines could take her months and money. People in her place sometimes give up, or stay small to avoid the next round of forms. How easy or hard it is to open a firm, keep it going and wind it up is called the ease of doing business. Many governments now run single-window portals, where several approvals can be applied for in one place.

Less reason to invent and improve. If returns are capped, or rules change often, firms have less reason to invest. A private bus operator whose fares have been frozen for years may keep running old buses instead of buying cleaner, safer ones. Passengers then pay in a different way: with slower, less comfortable journeys.

9.5 Reading the price puzzle

Economics will not tell you tomorrow's price of tomatoes. What it gives you is a way of investigating any price change, much as a detective works through clues. Here is one case, worked through.

Work through the same steps whenever a price surprises you, and a price tag stops being a puzzle. It becomes a clue to what buyers, sellers and governments are doing around you.