The purpose of QE is to reverse this contraction. But if debt deflation is so easy to fix, then why have the Fed's massive attempts to pull this maneuver off failed to revive the economy? And why is Japan still suffering from deflation after 20 years of quantitative easing?
The reason for this is clear; Japan's debt has ballooned to over $12 trillion and is now 237% of their GDP. So, what's a government and central bank to do? The answer of course is enacting yet another new fiscal stimulus package that will be monetized by the BOJ.
However, in contrast to what passes for the economic wisdom of today, an increase in the rate of sovereign bond yields would be a function of deterioration in their credit, currency and inflation risks. But it would never be because of an increase in the prospects for growth.