TOKYO -- Downward pressure on the yen is growing, with the Japanese currency touching 115 to the dollar, a four-year low. This compares to an equilibrium exchange rate of just below under 100 yen to the dollar, based on the raw economic strength of Japan versus other countries.

Datawatch
Yen selling continues despite positive real interest rates
Actual exchange rate stands at 9.6 yen lower than theoretical value