单选题 A scientist who wants to predict the way in which consumers (消费者) will spend their money must study consumer behavior. He must obtain data both on the resources of consumers and on the motives that tend to encourage or discourage money spending.
If an economist was asked which of three groups borrow most -- people with rising incomes, stable incomes, or decreasing incomes -- he would probably answer, those with decreasing incomes. Actually years 1947-1950, the answer was: people with rising incomes.
People with decreasing incomes were next and people with stable incomes borrowed the least. This shows us that traditional assumptions(假设) about earning and spending are not always reliable. Another traditional assumption is that if people who have money expect prices to go up they will hasten to buy. If they expect prices to go down, they will postpone buying. But research surveys have shown that this is not always tree. The expectations of price increases may not stimulate buying.
The investigations mentioned above were carried out in America; the condition most helpful to spending appears to be price stability. If prices have been stable and people consider that they are reasonable, they are likely to buy. Thus, it appears that the common business policy of maintaining stable prices is based on a correct understanding of consumer psychology(心理学).

单选题 According to the passage, if a scientist wants to predict the way consumers spent their money, be must ______.

单选题 In the second paragraph, one traditional assumption is that people with ______ incomes borrow most.

单选题 According to the research surveys in the second paragraph, it has proved that ______.

单选题 ______ is most helpful to spending.

单选题 According to the passage, if a department store wants to attract more consumers, it must ______.