1. Has there been an increase or decrease in demand? Factors that could shift the demand more include changes in preferences, changes in income, changes in the price of substitutes or complements, or changes in the number of consumers in the market. 2. Has there been an increase or decrease in supply? Factors that could shift the supply more include changes in costs of materials, wages, or other inputs; changes in technology; or changes in the number of rms in the market. 3. Draw a supplyand-demand graph to explain this change. He sure to label your graph and clearly indicate which curye shifts