📉 Demand and Law of Demand

Demand analysis begins with a simple idea: buyers do not just want goods, they must also be willing and able to purchase them. That is why demand is more precise than desire.

---

What Is Demand?

Demand is the quantity of a commodity that consumers are willing and able to buy at different possible prices during a given period of time.

This definition has three important parts:

• willingness to buy
• ability to pay
• a period of time such as a day, week, month, or year

So desire alone is not demand. A person may want a tractor, but unless purchasing power exists, that desire does not become economic demand.

---

Individual Demand and Market Demand

Individual Demand

An individual demand schedule shows different quantities of a commodity that one consumer would buy at different prices, other things remaining constant.

Market Demand

Market demand is the total demand of all consumers in the market. It is obtained by adding the individual demand schedules of all buyers.

This distinction matters in agricultural markets because:

• household-level consumption explains individual demand
• mandi-level or regional quantity movement reflects market demand

---

Demand Schedule and Demand Curve

A demand schedule presents the relationship between price and quantity demanded in tabular form.

Example:

Price of rice (Rs/quintal)	Quantity demanded (tonnes/month)
950	5000
900	5100
850	5200
800	5300
750	5400
700	5500

When the same relationship is shown graphically, it becomes a demand curve.

The usual shape of the demand curve is downward sloping, showing an inverse relation between price and quantity demanded.

---

Determinants of Demand

Demand depends on more than price alone. Major determinants are:

1. Price of the Commodity

When price rises, quantity demanded generally falls. When price falls, quantity demanded generally rises.

2. Income of the Consumer

For normal goods, higher income raises demand. For inferior goods, demand may fall as income rises.

3. Tastes and Preferences

Fashion, habit, advertisement, culture, and awareness can all affect demand.

4. Prices of Related Goods

• substitutes: tea and coffee
• complements: milk and sugar, bread and butter

If the price of a substitute rises, demand for the commodity may increase. If the price of a complement rises, demand may decline.

5. Population

Larger population usually means larger market demand.

6. Distribution of Income

If income is concentrated among the rich, demand for luxury goods may be higher. More equitable distribution can strengthen mass demand for essential goods.

7. Expectations About Future Prices

If buyers expect prices to rise in the near future, present demand may increase.

---

Law of Demand

The law of demand states:

other things remaining the same, the quantity demanded of a commodity varies inversely with its price

That means:

• if price rises, quantity demanded falls
• if price falls, quantity demanded rises

This inverse relationship is the basic reason the demand curve slopes downward.

---

Why the Law of Demand Operates

The law works because of several economic reasons.

Diminishing Marginal Utility

As more units of a good are consumed, the extra satisfaction from each additional unit declines. Therefore consumers are willing to buy additional units only at lower prices.

Substitution Effect

When the price of a good falls, it becomes relatively cheaper than substitutes, so buyers substitute it for other goods.

Income Effect

A fall in price increases the real purchasing power of income, so the consumer can buy more.

More Buyers Enter the Market

At lower prices, some consumers who previously could not afford the good may begin purchasing it.

---

Movement Along Demand Curve vs Shift in Demand

This distinction is exam-critical.

Extension and Contraction of Demand

When quantity demanded changes because of a change in the commodity's own price, it is a movement along the same demand curve:

• extension: increase in quantity demanded due to fall in price
• contraction: decrease in quantity demanded due to rise in price

Increase and Decrease in Demand

When demand changes because of factors other than own price, the entire demand curve shifts:

• increase in demand: rightward shift
• decrease in demand: leftward shift

Causes include changes in income, tastes, prices of related goods, and expectations.

---

Relevance in Agriculture

Demand analysis is important in agriculture because it helps explain:

• food demand in urban and rural households
• response to price changes in cereals, pulses, milk, fruits, and vegetables
• market planning for perishables
• consumption effects of subsidy, inflation, and income change

For farm policy and agribusiness decisions, understanding demand is as important as understanding production.

Summary Cheat Sheet

Topic	Quick Recall
Demand	Quantity buyers are willing and able to purchase at different prices over a period
Individual demand	Demand of one consumer
Market demand	Sum of demand of all consumers
Demand schedule	Tabular relationship between price and quantity demanded
Demand curve	Graphical representation of demand
Law of demand	Price and quantity demanded move inversely, other things constant
Main determinants	Price, income, tastes, related goods, population, expectations
Extension/contraction	Movement along curve due to own price change
Increase/decrease in demand	Shift of curve due to non-price factors
Why demand slopes down	Diminishing utility, substitution effect, income effect