Consider the market for strawberries. There is an increase in the price of scones, which is a complement to strawberry jam. At the same time, a period of poor summer weather results in a smaller harvest of strawberries this season than the previous season. Consider the first scenario (the change in the price of scones). The effect of this change is to shift the Answercurve to the Answer. Consider the second scenario (the impact of the weather). The effect of this change is to shift the Answer curve to the