正如二楼分析的，预期通货膨胀率升高会使名义利率升高，达到新的均衡

用数学表示，如名义利率为i，实际利率为r，预期通货膨胀率为 X^e = (P₁^e-P) / P

则在市场出清后，名义利率与实际利率及预期通货膨胀率的关系可表示为：

1+i= (1+r) * (1+ X^e )

由于右边= 1+ r + X^e + r *X^e , r * X^e 相对于其他各项太小，可忽略不计，因此，以上等式也可近似写成：

i = r + X^e ，名义利率与预期通货膨胀率之间有一对一的变动

我觉得３楼说得也太复杂了，通货膨胀就是因为output gap become too narrow and there is mere capacity for the economy to develop. The effect of increment in aggregate demand is mainly on the general price,thus inflation rises. If the expectation of inflation is too high,raising interest rate will have the effect of cutting down consumption,and drive up the exchange rate and thus reduce export,raise import,what is more, it will reduce investment because the payback is high.

According to AD=C+I+G+X-M,consumption and investment, export all fall and import rises then AD falls. AD falls will lead to less inflationary effect. Therefore, the interest rate will be high.

PS: AD=aggregate demand

C=consumption I=investment G=government spending X=export M=import

四楼的大哥真是厉害!别的不说,英语太好了/"钱"途无量啊!