I could devote a dozen posts to Scott Sumner’s latest essay-length entry.  But I’ll limit myself to the highlights:

Stop worrying about inflation.

…Laffer is too good an economist to say anything blatantly false, but the entire tone of his WSJ piece is that high inflation is just around the corner…

One reason that I was so discouraged by this piece is that Laffer
was one of the “new monetary economists” of the early 1980s who
understood that traditional monetarism had important defects.  Rather
than focusing on the money supply, Laffer suggested that we needed to
look at forward-looking market indicators such as the price of gold. 
Today we have an even better forward-looking indicator–TIPS spreads. 
And it is very clear that investors are not worried about high
inflation.  Not now, not in 10 years, and not in 20 years.

Krugman doesn’t really believe in the liquidity trap.

Many Keynesians assume that monetary stimulus is ineffective during a
liquidity trap.  Krugman definitely does not believe that, indeed he
specifically argues that only conventional monetary policy tools are
ineffective in a liquidity trap.  He acknowledges that unconventional
tools (such as an inflation target) might be highly effective, but also
that they might be politically unacceptable.

Krugman, ants, and central banks.