what does an income elasticity of demand of 1 50 mean 
since the value is positive the good is elastic it implies that for every 1 increase in income people will demand an increase of 1 5 in the number of goods thus if the average income is 100 000 and at that level of income people desire 70 meals out a year they would demand 71 meals a year if income rose to 101 000 1 5 of 70 1 05 meals more 