how does cross elasticity of demand differ from the cross elasticity of supply 
the cross elasticity of supply measures the proportional change in the quantity supplied or produced in relation to changes in the price of a good this is in contrast to changes in demand for two goods in response to prices the bottom lineprices and demand often go hand in hand in economics economic theory generally dictates that demand for another good generally goes up when the price of one good goes up too this is called the cross price elasticity of demand you can easily calculate this figure by taking the percentage change in the quantity demanded of one good by the percentage change in price for another good 