A scientist who does research in economic psychology and who

A scientist who does research in economic psychology and who wants to predict the way in which consumers 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 were asked which of three groups borrow most ---people with rising incomes,stable incomes,or declining incomes---he would probably answer:those with declining incomes.Actually,in the years 1947~1950,the answer was:people with rising incomes.People with declining incomes were next and people with stable incomes borrowed the least.This shows us that traditional assumptions 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 true.The expectations of price increases may not stimulate buying.
请帮忙翻译这段话

一个科学家谁做研究在经济心理学,谁想预测用消费者会花他们的钱必须研究消费者行为.他必须获得基准两者都在消费者的资,在动机,倾向于鼓励或阻碍钱花.就一个经济学家被要求哪的三个小组借用最---people同收入增长,稳定的收入,或下降incomes---he将大概答案:那些同下降收入.其实,在岁1947~1950,答案:使充满收入增长.使充满下降收入未来,使充满稳定的收入借最少.这个节目我们如此惯例的臆说对赚,花不一定可靠.另一惯例的的臆说是,如果人谁有钱期望价格用大牌打,他们会赶紧购买.如果他们期望价格下跌,他们会推迟买.然而研究调查显示了,这是不一定真.预期极宝贵的提高可能不刺激买.