What is Law of Demand?
Law of Demand states that other things being equal, there is a negative relation between demand for a commodity and its price.
In other words, when price of the commodity increases, demand for it falls and when price of the commodity decreases, demand for it rises, other factors remaining the same.
The above diagram shows the demand curve which is downward sloping. Clearly when the price of the commodity increases from price p3 to p2, then its quantity demand comes down from Q3 to Q2 and then to Q3 and vice versa.
Must read: Windfall tax – Definition, Purpose, Calculation, Impact
Law of Demand in case of Normal Goods
The quantity of a good that the consumer demands can increase or decrease with the rise in income depending on the nature of the good. For most goods, the quantity that a consumer chooses, increases as the consumer’s income increases and decreases as the consumer’s income decreases. Such goods are called Normal Goods. Thus, a consumer’s demand for a normal good moves in the same direction as the income of the consumer.
Law of Demand in case of Inferior Goods
However, there are some goods the demands for which move in the opposite direction of the income of the consumer. Such goods are called Inferior Goods. As the income of the consumer increases, the demand for an inferior good falls, and as the income decreases, the demand for an inferior good rises. Examples of inferior goods include low quality food items like coarse cereals.
Law of Demand in case of Complementary Goods
The quantity of a good that the consumer chooses can increase or decrease with the rise in the price of a related good depending on whether the two goods are substitutes or complementary to each other. Goods which are consumed together are called complementary goods.
Examples of goods which are complement to each other include tea and sugar, shoes and socks, pen and ink, etc. Since tea and sugar are used together, an increase in the price of sugar is likely to decrease the demand for tea and a decrease in the price of sugar is likely to increase the demand for tea. Similar is the case with other complements. With the increase in price of complement, demand reduces.
Law of Demand in case of Substitute Goods
In contrast to complements, goods like tea and coffee are not consumed together. In fact, they are substitutes for each other. Since tea is a substitute for coffee, if the price of coffee increases, the consumers can shift to tea, and hence, the consumption of tea is likely to go up. On the other hand, if the price of coffee decreases, the consumption of tea is likely to go down. The demand for a good usually moves in the direction of the price of its substitutes.
External link: https://en.wikipedia.org/wiki/Law_of_demand
PRACTICE QUESTIONS
QUES . Consider the following statements: UPSC 2021
Other things remaining unchanged, market demand for a good might increase if
1. price of its substitute increases
2. price of its complement increases
3. the good is an inferior good and income of the consumers increases
4. its price falls
Which of the above statements are correct?
(a) 1 and 4 only
(b) 2, 3 and 4
(c) 1, 3 and 4
(d) 1, 2 and 3
Answer (a)
