INCOME ELASTICITY DEMAND

The price of a product and its substitutes of consumer’s income in the bases of demand for the product the relation ship between quantity demanded and income of positive nature and income elasticity .The demand of goods and services increases with the increases of the costomer income .the respectiveness  of demand to the change income is know as income elastic demand.    
        If the consumer income is increases the demand is also increases.                                                  
         if the consumer income decreases  the demand is also decreases.                    
 The reason is that when income increases consumer switch over the consumption of superior subsititutes for instance when income rises people prefer to travel mor by plane and less in train