A function that can either be the actual evaluation of an individual’s utility or an economist’s convenient representation of an individual’s preferences. There is in principle no reason why an individual cannot evaluate the utility of different outcomes using a utility function. If they do, then the first interpretation applies. Note that ‘an individual’ can be broadly interpreted to include organizations, and an organization may employ a utility function to guide its decision-making. Economists employ utility functions as a convenient representation of preferences that permits mathematical analysis. A utility function represents a set of preferences if the function has a higher value for consumption bundle x than for consumption bundle y if, and only if, x is preferred to y. The restrictions that must be placed on preferences to ensure a utility function exists that represents them are very weak. Moreover, a rational individual will act as if they maximize the utility function. See also indirect utility function; separable utility function.