It's plausible that QE had scant real effect on the economy says Fed's Lacker

Lacker's turn on the soap box

• Monetary policy's ability to affect real economic activity is limited and temporary
• Monetary policy is uniquely suited to control inflation
• Recent inflation figures do not imply a permanent departure from the Fed's target rate
• Caution is warranted in policy responses to financial markets

That's pretty strong comments on the effects of QE from a central banker and that could well be behind the fall in USDJPY just now