Empirical Study on the Currency Exchange Market. Determinants on the Exchange Rate of the U.S. Dollars and the Japanese Yen by the Regression Analysis.

It is widely known that in the exchange rate market there are 3 factors influential to determine the currency exchange rate between the related countries in theory; i.e., the interest rate, inflation, and expectation on the exchange rate. This paper aims to find how the exchange rate between U.S. dollar and Japanese Yen, both of which are widely recognized as major currencies in the international financial market, are affected by the 4 key variables selected here in this paper related to these 3 factors under the recent inflationary economic environment; i.e., interest rate yield of the 2 year treasury bond, inflation rate, and the two moving average of the exchange rate to be considered as rational expectation on the movement of the exchange rate. As result it is our discovery that the selected predicator variables have been influential to the daily volatility and monthly movement of the exchange rate of the Japanese Yen /US $ with evidence the two different models of the regression analysis are able to show the exchange rate are significantly correlated with these 4 key variables and strongly affected by them. Also, during the period of total 30 months from the beginning of Y2021 through the middle of Y2023 this empirical analysis has been conducted, neither interest rate parity nor the purchasing power parity, both of which are the well-known theory of the international economy, did hold due to the reason value of U.S. $ have been kept stronger along with continuous increase in the interest rate yield in the U.S than that in Japan to cope with the faster inflation speed in the U.S economy.