It is 28 between and movies, 22 between and 3, and so on The slope between and movies is zero; the total utility curve between these two quantities is horizontal Marginal Utility The amount by which total utility rises with consumption of an additional unit of a good, service, or activity, all other things unchanged, is marginal utility The first movie Mr Higgins sees increases his total utility by 36 units Hence, the marginal utility of the first movie is 36 The second increases his total utility by 28 units; its marginal utility is 28 The seventh movie does not increase his total utility; its marginal utility is zero Notice that in the table marginal utility is listed between the columns for total utility because, similar to other marginal concepts, marginal utility is the change in utility as we go from one quantity to the next Mr Higgins’s marginal utility curve is plotted in Panel (b) of Figure 7.1 "Total Utility and Marginal Utility Curves" The values for marginal utility are plotted midway between the numbers of movies attended The marginal utility curve is downward sloping; it shows that Mr Higgins’s marginal utility for movies declines as he consumes more of them Mr Higgins’s marginal utility from movies is typical of all goods and services Suppose that you are really thirsty and you decide to consume a soft drink Consuming the drink increases your utility, probably by a lot Suppose now you have another That second drink probably increases your utility by less than the first A third would increase your utility by still less This tendency of marginal utility to decline beyond some level of consumption during a period is called the Attributed to Libby Rittenberg and Timothy Tregarthen Saylor URL: http://www.saylor.org/books/ Saylor.org 355