USD/JPY: testing the 50% retracement of Abe yen sell-off - BBH

Analysts at Brown Brothers Harriman explained that the JPY100.60 area corresponds to a 50% retracement of the Abe-inspired yen sell-off.  

Key Quotes:

"The 61.8% retracement is near JPY94.60.  

That seems to be where the greenback is headed.  

This area corresponds to what some economists might see as value.  

Purchasing power parity is that level that economic theory holds currencies will gravitate around in the long-run, based on the law of one price.  

The OCED estimate fair value (PPP) for the dollar-yen exchange rate is near JPY98.  

What other level does dollar-yen gravitate around in the long-run? 

Currencies gravitate around a long-term moving average by definition.  The 120 month (10-year) moving average of dollar-yen is a rough and ready estimate of PPP.  It is found near JPY99.80."