Which of the following causes a movement along a given demand curve for a goods ?

Question

Accepted Answer

The correct option is 4:
Change in own price of the goods.

In economics, the demand curve graphically represents the relationship between the price of a good and the quantity demanded, assuming all other factors remain constant (the *ceteris paribus* condition). A movement *along* a given demand curve, also known as a change in quantity demanded, is exclusively caused by a change in the good's own price. When the price of the good changes, consumers react by moving to a new point on the existing curve, which illustrates the inverse relationship between price and quantity demanded (the Law of Demand). An increase in the price causes a contraction of demand (upward movement), and a decrease in price causes an extension of demand (downward movement).

The incorrect option is 1:
Change in income of the Consumer. A change in consumer income is a non-price determinant of demand. When income changes, the entire demand curve shifts (either inward or outward), representing a change in demand, not a movement along the curve.

The incorrect option is 2:
Change in price of complementary goods. Complementary goods are used together (like cars and petrol). A change in the price of a complement causes the demand curve for the original good to shift. This is also a non-price determinant, causing a shift in demand.

The incorrect option is 3:
Change in price of substitute goods. Substitute goods can be used in place of one another (like tea and coffee). A change in the price of a substitute will cause the demand curve for the original good to shift, as consumers switch their preferences. This is categorized as a change in demand, not a change in quantity demanded.