国际金融中irp、ife、ppp的区别是什么？

作者：国际期货专业户
链接：https://www.zhihu.com/question/**7/answer/**2
来源：知乎
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。beth miller does not believe that the international f**her effect(ife)holds.current one-year interest rates in europe are 5 percent,while one-year interest rates in the u.s.are 3 percent.beth converts$100,000 to euros and invests them in germany.one year later,she converts the euros back to dollars.the current spot rate of the euro **$1.10.
a.according to the ife,what should the spot rate of the euro in one year be?e(e)=(f – 1.1)/1.1=(3%– 5%)/(1+5%)
f=(3%– 5%)/(1+5%)×1.1 – 1.1=– 0.02/1.05×1.1+1.1 ≒ 1.079
b.if the spot rate of the euro in one year **$1.00,what ** beth’s percentage return from her strategy?美金换欧元：$100,000/1.10 ≒ €90,909.09
投资欧元一年后所获得：€90,909.09×1.05=€95,454.55
欧元换美金：€95,454.55×1.00=$95,454.55
投资报酬率：($95,454.55 –$100,000)/$100,000 ≒ –4.55%
c.if the spot rate of the euro in one year **$1.08,what ** beth’s percentage return from her strategy?美金换欧元：$100,000/1.10 ≒ €90,909.09
投资欧元一年后所获得：€90,909.09×1.05=€95,454.55
欧元换美金：€95,454.55×1.08=$103,090.91
投资报酬率：($103,090.91 –$100,000)/$100,000 ≒ 3.09%
d.what must the spot rate of the euro be in one year for beth’s strategy to be successful?若当期汇率 ≧ 1.079，则策略成功
简单来讲的话
irp和ife是不同货币的汇率及利率问题，ppp是工程领域的**投资工程