Change in Demand
Change in demand causes the demand curve to shift. The demand for a commodity is determined by many factors other than price. These factors are income, taste and habits, price of related goods, income distribution, climatic and weather conditions etc. If any one or more factors undergoes a change, demand changes. This is called change in demand. For example price of cold drinks remaining constant, if winter changes into summer, then demand for cold drinks will rise. Here demand changes not due to the change in price but due to the factors other than price. This leads to the shift of demand curve to the right.
The concept of change in demand can be illustrated in above diagram
In Fig..8, DD is the original demand curve. OP is the price which remains constant throughout. OQ is the original quantity demand at OP price. Now if non-price determinants like weather changes to summer, then demand for cold drinks goes u. Hence the demand curve shifts to the right to D1D1 position. As a result demand increases from OQ to OQ1. The opposite will happen if summer changes to winter and the demand curve will shift to the left to D2D2 position.
