目前,美元降息,其利息仍然比人民币高(尤其是实际利息 real rate)

原始套利案例告诉我们,只要两国存在利差并且资金没有流动成本(三项输金费)和障碍(政府管制),就会发生套利引起的资金流动,并通过供求关系最终导致两国货币汇率变动----利息损失汇价补-----利息评价理论

而现在,美国利率下降,意味着持有人民币的机会成本下降,套利者面对人民币的刚性升值预期,会更加肆无忌惮地购入人民币来获得升值好处.

以上所有的分析都是基于美元利率长期高于人民币利率的事实.这种利差的存在可以算得上是一种对中国的保护,但显然现在这种利差减小了,热钱流入就更猖獗了.

There are lots of reasons supporting to that question.

Apparently to say, since Chinese central bank uses managed exchanged rate regime, a fall in the value of US currency will cause Chinese Yuan to appreciate. For example, 8RMB = 1USD before, 1USD in the past absolutely is not equal to and more than 1USD currently, then, 8RMB should be > 1USD, therefore, Chinese yuan has to be appreciated relating with US dollar.

However, we can use another terminology to analysis as well.  ----- From the point of GPL(general price level)

As we all know, the Chinese GPL is tooooo hot, it needs to cool down. The depreciation of US currency relatively helps the GPL of Chinese final goods and service to decrease, ceteris paribus, as well as its AD curve.

1) International substitution effect: Chinese economy will substitute cheaper imports for domestic final goods and services, therefore, more imports and less exports comparatively.

2) Real income effect: as nominal income does hold,  Chinese high GPL of domestic final goods and services will decrease it real income, less products that a householder can consume, as a result, consumption falls.

3) Real Balance effect: A high GPL can decrease the real balance of householders' saving, which might influence them to consume less and save more, then... you can image.(lead to a new era - monetary term analysis will begin)

Additional hint: This thread belongs to the range of Macro - economy, for the micro part, it talks about firms, families, and seperated persons. For the macro part, it talks about countries, banks, etc. And also, it is a good question for revision and welcome the test, but not good for discussing, because toooo many ways that can be solved. 

[此贴子已经被作者于2008-2-1 19:15:47编辑过]

当美国降息时，中美利差减小，假设将一美元分别存在美国和中国。美国的利率假设为ra，中国利率假设为rc。利用直接标价法，假设汇率为f。那么在中国存一年本利和为f(1+rc),在美国为（1+ra).假设资金是自由流动的，则当获利不同时会发生资金的流动，直到获利相等时，达到均衡。资金停止流动。即当f(1+rc)=（1+ra）时，均衡。因此f=(1+ra)/(1+rc).美国降息。则（1+ra）减小，f减小，即在直接标价法下，汇率降低，则人民币会升值。

从理论上将，由于美国进行加息话会加大中美两国的利差。而这样会吸引更多的人将美元兑换成人民币，然后将人民币进行存款或投资。这样就使得人民币的需求增大了，这样会使人民币的价格上升，换句话说人民币升值了。而作为中国而言，本来同样可以通过减息缩小利差，但由于我国目前仍处于通货膨胀的压力之下，减息反而会加剧这种情况。所以对于目前中国正面临一个两难的局面。

可不可以把钱换成资源什么的，能够长期保值的东西

不错

美联储降息会使世界市场上流通的美元增多，这样就会加速人民币的升值速度。
实际上世界一直面临通胀的压力，美联储近些年的利率一直在上升，从1%一只涨到5.25%.但是最近美国的次债危机很严重，市场上美元严重不足，在联储注入大量资金无效的情况下，只好采取降息的下策。影响人民币的汇率只是个间接的效应。

换成贵重金属,保值的可能性要大一些.毕竟这属于稀缺资源,纸币却不是.你可以自己看一下这50年各国黄金牌价就看的出来了!不过金属价格多数情况下也不会飚升,风险和收益都相对小很多!