How can two different countries have different interest rates?

那这两个国家怎么会有不同的利率呢
You would think,

你可能会想
well wouldn't an investor always invest in the country

一个投资者不会总把钱投在
with the higher interest rate?

一个高利率的国家吧
Why not if it's riskless?

如果没有风险的话为什么不呢
Well, there is risk and that's exchange rate risk.

实际上有风险存在即汇率风险
You can get rid of the risk by taking a forward contract.

但是你可通过远期合约来规避风险
You could say, if you're living in Japan,

比如说你住在日本
I note that interest rates are higher in the U.S. than Japan,

你注意到美国的利率比日本高
so I'm not going to go--I'm not going to invest in yen bonds;

所以你肯定不会去投资日本债券
I'm going to invest in U.S. bonds.

相反的把钱都拿去投资美国债券
Then, I'm going to cover myself by making a forward contract

然后你为了保证到时能拿回日元