QUESTIONS

1. Complete the following table and answer the questions below: LO1

a. At which rate is total utility increasing: a constant rate, a decreasing rate, or an increasing rate? How do you know? b. “A rational consumer will purchase only 1 unit of the product represented by these data since that amount maximizes marginal utility.” Do you agree? Explain why or why not. c. “It is possible that a rational consumer will not purchase any units of the product represented by these data.” Do you agree? Explain why or why not.

Answer: Missing total utility data, top – bottom: 18; 33. The missing total utility for the second unity can be found by adding the marginal utility (change in utility) to the total utility for the first unit. By consuming the second unit, 8 more units of utils are added; thus total utility is 18 (= 10 + 8). Missing marginal utility data, top – bottom: 7; 5; 1. The missing marginal utility values are found by subtracting the total utility for the previous unit consumed from the total utility of the unit with the missing value (the change in utility). The marginal utility for the third unit is 7, which equals 25 (total utility for the third unit) minus 18 (total utility for the second unit). (a)A decreasing rate; because marginal utility is declining. (b)Disagree. The marginal utility of a unit beyond the first may be sufficiently great (relative to product price) to make it a worthwhile purchase. Consumers are interested in maximizing total utility, not marginal utility. (c)Agree. This product’s price could be so high relative to the first unit’s marginal utility that the consumer would buy none of it.

2. Mrs. Simpson buys loaves of bread and quarts of milk each week at prices of $1 and 80 cents, respectively. At present she is buying these products in amounts such that the marginal utilities from the last units purchased of the two products are 80 and 70 utils, respectively. Is she buying the utility-maximizing combination of bread and milk? If not, how should she reallocate her expenditures between the two goods? LO2

Answer: Mrs. Wilson is not buying the utilitymaximizing combination of bread and milk because the marginal utility per cent spent on each good is not equal. The marginal utility per cent of bread is 0.8 (= 80 utils/100 cents); the utility per cent of milk is 0.875 (= 70 utils/80 cents). Mrs. Wilson should buy more milk and less bread.

3. How can time be incorporated into the theory of consumer behavior? Explain the following comment: “Want to make millions of dollars? Devise a product that saves Americans lots of time.” LO2

Answer: Time is money. This expression is a timesaving way of making the point that for a person who can make so much per hour, every hour spent not working is so much money not made. A person can be said to “consume” a ball game or an evening at the theater. If the ball game costs $10 and the theater $20, at first sight one could say the ball game is a better deal. But if the person makes $20 an hour and is forgoing this in taking the time off, then we must take into account the time spent at the ball game and at the theater. If the ball game goes into extra innings and takes 4 hours, then its total cost is $90 (= $10 + $80). If the theater takes 3 hours, its total cost is $80 (= $20 + $60). Assuming the marginal utility of the ball game and attending the theater are the same, the theory of consumer behavior (with time taken into account) would therefore have this consumer going to the theater.

4. Explain: LO2

a. Before economic growth, there were too few goods; after growth, there is too little time. b. It is irrational for an individual to take the time to be completely rational in economic decision making. c. Telling your spouse where you would like to go out to eat for your birthday makes sense in terms of utility maximization.

Answer:

(a)Before economic growth, most people lived at...