An increase in the price of a substitute would be assumed to decrease output of good X as producers move resources into production of the substitute. For example, if a brewer is producing both beer and lager and there is an increase in the price of lager then resources should flow into lager production and away from beer to take advantage of the increased relative profitability of lager. There is therefore an inverse relationship between the price of substitutes and the supply of good X The supply curve for good X would shift to the right if the price of a substitute fell, and vice (see Figure 5.2)