The following appeared in a memorandum from a vice president of the Megamart department store chain. "For the third year in a row, the average household income in our country has risen significantly. That prosperity means that families are likely to be sp

In this memo the vice president of Megamart concludes that Megamart should expand its line of products related to leisure activities. To support this claim the memo points out that for three years in a row the average household income nationwide has risen. However, close inspection of the argument reveals several logical problems, which render it unconvincing as it stands.

First of all, the claim relies on two threshold assumptions about rising income. One is that this trend will continue in the future; if it does not then the proposed course of action is unlikely to result in increased profits for Megamart. The other threshold assumption is that the cost of living is not also increasing at least at a commensurate rate. Yet it is entirely possible that living costs have risen to meet or even exceed the rise in income.

If so, Megamart would in all likelihood sell fewer leisure products than otherwise. Even assuming that discretionary income is rising and will continue to rise, the argument relies on the additional assumption that people will spend this discretionary income on leisure products. However, the memo provides no evidence to substantiate this assumption. Perhaps people are increasing their savings rather than spending their additional income. If so, this fact would significantly undermine the vice president's claim that demand for leisure products is increasing, and therefore that Megamart would benefit by offering more such products.

Yet another problem with the argument involves the reason why average income has risen in the first place. It is entirely possible that income has risen because people have been working more hours. If so, then in all likelihood people have less leisure time, in which case they will not spend more money on leisure products--simply because they have less time for leisure pursuits. Without addressing this issue, the vice president cannot convince me that Megamart should expand its line of leisure products.

In conclusion, the vice president's argument is unconvincing as it stands. To strengthen it the vice president must provide strong evidence that discretionary income is rising and will continue to rise. The vice president must also show that people will in fact choose to spend this income on leisure products, and that people have enough free time for leisure pursuits in the first place.