Figure10-4Marginal Utility per Dollar Sammy’s optimal consumption bundle is at point W, where his marginal utility per dollar spent on wings, MU_W/P_W, is equal to his marginal utility per dollar spent on potatoes, MU_P/P_P. This illustrates the utility-maximizing principle of marginal analysis: at the optimal consumption bundle, the marginal utility per dollar spent on each good and service is the same. At any other consumption bundle on Sammy’s budget line, such as bundle B in Figure 10-3, represented here by points B_W and B_P, consumption is not optimal: Sammy can increase his utility at no additional cost by reallocating his spending.