Chapter 9 – The Price Puzzle: What Drives the Market
In everyday life, we observe that prices of vegetables, fruits, fuel, clothes, mobile phones, hotels and many other goods and services change over time. Why do prices change? How are prices determined in a market? This chapter explains demand, supply, price determination, market equilibrium and the factors that influence market outcomes.
1. What Is a Market?
A market is not simply a physical place where buying and selling takes place. It is a system through which buyers and sellers interact to exchange goods and services.
Markets may be physical or digital. Online platforms, mobile applications and internet-based businesses are also examples of modern markets.
2. Main Components of a Market
- Consumers or buyers
- Producers or sellers
- Goods and services
- Prices
- Demand
- Supply
- Information and market conditions
3. Importance of Price
Price is the amount of money paid to obtain a good or service.
Price also works as an important signal in a market. Changes in price can influence the decisions of both consumers and producers.
If the price of onions suddenly rises, some consumers may reduce their purchases. At the same time, higher prices may encourage producers to increase production.
4. Demand
Demand does not simply mean liking or wanting a product. In economics, demand refers to the quantity of a good that consumers are willing and able to buy at a particular price during a particular period.
5. Main Elements of Demand
- Desire to purchase
- Ability to pay
- A particular price
- A particular time period
6. Law of Demand
Other things remaining constant, the quantity demanded of a good generally decreases when its price rises and increases when its price falls.
Price ↑ → Quantity Demanded ↓
Price ↓ → Quantity Demanded ↑
7. Factors Affecting Demand
- Price of the good
- Consumer income
- Prices of related goods
- Tastes and preferences
- Season
- Expectations about future prices
- Number of consumers
8. Income and Demand
Changes in income can affect the purchasing ability of consumers. For normal goods, an increase in income may lead to an increase in demand.
However, the relationship is not identical for every good. For some inferior goods, demand may decrease when income rises because consumers may shift towards better alternatives.
9. Related Goods
Some goods are substitutes while others are complements.
| Type | Meaning | Example |
|---|---|---|
| Substitutes | One good can be used in place of another | Tea and coffee |
| Complements | Goods that are commonly used together | Car and petrol |
10. Demand Curve
A demand curve shows the relationship between the price of a good and the quantity demanded at different prices.
Under normal conditions, the demand curve slopes downward because quantity demanded generally falls when price rises.
11. Supply
Supply refers to the quantity of a good that producers are willing and able to sell at a particular price during a particular period.
12. Law of Supply
Other things remaining constant, producers generally offer a larger quantity for sale when the price of a good increases.
Price ↑ → Quantity Supplied ↑
Price ↓ → Quantity Supplied ↓
13. Factors Affecting Supply
- Price of the good
- Cost of production
- Prices of inputs
- Technology
- Taxes and government policies
- Number of producers
- Expectations about future prices
- Natural conditions
14. Cost of Production
If wages, raw material prices, electricity costs, transportation costs or other input costs increase, production may become more expensive. Producers may then reduce supply or attempt to charge higher prices.
15. Technology and Supply
Improved technology can reduce production costs and enable producers to supply a larger quantity of goods.
16. Supply Curve
A supply curve shows the relationship between price and the quantity that producers are willing to supply.
Under normal circumstances, the supply curve slopes upward.
17. Market Demand and Market Supply
The demand of an individual consumer is individual demand. The combined demand of all consumers in a market is market demand.
Similarly, the combined supply of all producers constitutes market supply.
18. Market Equilibrium
Market equilibrium occurs at a price where the quantity demanded equals the quantity supplied. This price is called the equilibrium price.
Quantity Demanded = Quantity Supplied
At this point, the plans of buyers and sellers are consistent with each other.
19. Excess Demand
When quantity demanded is greater than quantity supplied at a particular price, there is excess demand.
Such a situation may create upward pressure on price, causing demand to fall and supply to rise.
20. Excess Supply
When quantity supplied is greater than quantity demanded at a particular price, there is excess supply.
Sellers may respond by reducing prices in an attempt to sell their unsold goods.
21. Price as a Market Signal and Incentive
Price performs both an informational and an incentive function in markets.
- Higher prices may encourage producers to increase production.
- Higher prices may discourage consumers from buying large quantities.
- Lower prices may increase consumer demand.
- Changes in price can influence the allocation of resources.
22. Why Do Prices Change?
Prices are not fixed permanently. Changes in demand and supply can cause market prices to change.
- Changes in weather
- Seasonal demand
- Festivals and special occasions
- Changes in production
- Changes in input costs
- Transportation costs
- Changes in income
- Technological changes
- Expectations about future prices
23. What Happens When Demand Increases?
If demand increases while supply does not immediately change, there may be upward pressure on the market price. A new equilibrium may emerge with changes in both price and quantity.
24. What Happens When Supply Decreases?
If supply decreases while demand remains unchanged, scarcity may arise and the market price may face upward pressure.
25. Consumers and Producers
Consumers communicate their preferences through demand. Producers respond through supply decisions.
The continuous interaction between consumers and producers influences prices and quantities traded in markets.
26. Markets Are Not Always Perfect
Real-world markets do not always have perfect information, equal bargaining power or perfect competition.
Problems such as monopoly power, imperfect information, external effects and weak consumer protection may occur.
27. Role of Government
Governments may regulate markets when necessary to protect consumers, promote fairness and address situations where markets alone may not produce desirable social outcomes.
- Consumer protection
- Prevention of unfair trade practices
- Availability of essential goods
- Provision of public goods
- Support for vulnerable groups
- Promotion of fair market practices
28. Public Goods
Some services provide benefits to society as a whole and may be difficult to provide adequately through individual market transactions alone. Government therefore has an important role in providing or supporting such services.
29. Market and Society
Markets are not only mechanisms for determining prices and profits. Market outcomes can also affect different sections of society, resource allocation and quality of life.
30. Advanced Concept: Change in Quantity Demanded vs Change in Demand
A change in the price of a good can cause a change in the quantity demanded along the same demand curve. However, changes in income, tastes, prices of related goods or the number of consumers can change the entire demand relationship.
31. Advanced Concept: Change in Supply
Changes in production costs, technology, taxes, the number of producers or natural conditions can change supply.
32. Market Equilibrium Is Dynamic
Market equilibrium is not a permanent condition. Whenever demand or supply changes, the market may move towards a new equilibrium.
Quick Revision
Demand ↑ → Upward pressure on price
Supply ↓ → Upward pressure on price
Demand ↓ → Downward pressure on price
Supply ↑ → Downward pressure on price
Market Equilibrium:
Quantity Demanded = Quantity Supplied
Important Terms
- Market: A system through which buyers and sellers interact to exchange goods and services.
- Demand: The willingness and ability to purchase a good at a particular price and time.
- Supply: The willingness and ability of sellers to offer a good at a particular price and time.
- Equilibrium Price: The price at which quantity demanded equals quantity supplied.
- Excess Demand: A situation where quantity demanded exceeds quantity supplied.
- Excess Supply: A situation where quantity supplied exceeds quantity demanded.
- Substitute Goods: Goods that can be used in place of one another.
- Complementary Goods: Goods that are generally used together.
Exam-Oriented Important Questions
- Why is a market more than just a physical place?
- What is meant by demand in economics?
- Explain the law of demand with an example.
- Explain the major factors affecting demand.
- What is the law of supply?
- Explain the factors affecting supply.
- What is equilibrium price?
- Distinguish between excess demand and excess supply.
- How does price act as both a signal and an incentive?
- What can happen to equilibrium price and quantity when demand increases?
- Why does an increase in production cost affect supply?
- Distinguish between substitute and complementary goods with examples.
- Explain the difference between a change in quantity demanded and a change in demand.
- Why can market equilibrium be considered a dynamic concept?
- Why may government intervention be necessary in some markets?