Causes of a rightward shift in demand curve of a commodity are as follows:
(i) Fall in income in case of inferior goods When income of the consumer decreases, he will increase the consumption of inferior goods, e.g. a person increases the consumption of dalda refined when his income falls.
(ii) Rise in income in case of normal goods When income of the consumer increases, he will increase the consumption of normal goods, e.g. a person increases the consumption of pure ghee when his income increases.
(iii) Rise in price of substitute goods. In case of such goods, increase in the price of one causes increase in the demand of other, e.g. tea and coffee. If the price of the tea rises, then demand for coffee rises.
(iv) Fall in price of complementary goods In case of such goods, decrease in the price of one causes increase in the demand of other, e.g. car and petrol. If the price of the petrol falls, consumer will demand more cars.
