问题如下：
Assume
that the DM country has what is considered a low-yield safe haven currency while
the EM country has a high-yield currency whose value is more exposed to
fluctuations in the global economic growth rate. All else equal, the exchange
rate for the EM currency will most likely depreciate if the:
选项：
A.long-run equilibrium
value of the high-yield currency is revised upward
nominal yield spread
between the EM and DM countries increases over time
expected inflation
differential between the EM and DM countries is revised upward
解释：
All
else equal, an increase in the expected inflation differential should lead to
depreciation of the EM currency.
解析：
real exchange rate (A/B) = equilibrium
real exchange rate + (real
interest rate B - real interest rate A)- (risk premium B - risk premium A)
根据上述公式。所以A、B选项错误。
在其它条件相同的情况下，预期通胀率的扩大会加两国的风险溢价之差，从而应会导致新兴市场货币贬值。所以C选项正确。
real exchange rate (A/B) = equilibrium real exchange rate + (real interest rate B - real interest rate A)- (risk premium B - risk premium A)
请问这是哪里的知识点，公式是怎么推导出来的呢？
