How real is deflation threat?  Why do economists worry more about deflation than inflation?  Where should investors put their money during deflationary environment.  On Point, my favorite program of WBUR, discusses these questions (source: NPR).

I also include a background chart:

(click to enlarge; source: CalculatedRisk)

Inflation (core CPI) in historical perspective:

(click to enlarge;  source: St. Louis Fed)