So with several pushes for devaluation and depreciation of the Malawi Kwacha, I recalled there is a way of assessing the exchange rate if a currency is over-valued or under-valued against another. So I did some research yesterday and came up with a script to help me with the assessment.
The Real Exchange Rate(Ereal) is the ratio of the Nominal Exchange Rate(Enominal) to the PPP Exchange Rate(Eppp). The following conditions are expected:
- When the Real Exchange Rate is equal to one, the currency is neither over-valued nor under-valued.
- When the Real Exchange Rate is less than one, the domestic currency is over-valued in relation to the foreign currency.
- When the Real Exchange Rate is greater than one, the domestic currency is undervalued in relation to the foreign currency.
- Enominal = Cdomestic/Cforeign, where Cdomestic is the domestic currency value and Cforeign is the foreign currency value.
- Eppp = Pdomestic/Pforeign, where Pdomestic is the Domestic Price of a Commodity, and Pforeign is the Foreign Price of the same Commodity.
- So let's assume that the dollar is our domestic currency and the euro is our foreign currency with the nominal exchange rate(Enominal) = $1.18/€1. a Big Mac costs $5.30 in the US and perhaps €4.50 in Europe. The script is able to evaluate that "The Foreign Currency is neither under-valued nor over-valued relative to the Domestic Currency."
- Suppose instead of €4.50, the Big Mac is selling at €5.40 due to inflation while the nominal exchange rate is the same. The script evaluates that "The Foreign Currency is 20% overvalued relative to the Domestic Currency."
- Let's compare the Chinese Yuan and the US Dollar: One US Dollar buys ¥6.8. A Big Mac costs $5.30 in the US, and costs ¥20 in China. The script evaluates that "The Foreign Currency is 45% under-valued relative to the Domestic Currency."
Domestic Currency: 1020Foreign Currency: 1Domestic Price: 41000Foreign Price: 58
This gives an evaluation that "The Foreign Currency is 44% overvalued relative to the Domestic Currency."