The Federal Reserve has gone on the offensive to sell its exit strategy to investors and the public, in the hopes that it can stall an increase in inflation expectations. The effort was first launched by Fed Board Governor Kevin Warsh, who argued in a Wall Street Journal editorial, followed by a speech, that when the time came for Fed tightening, policymakers might have to move quickly. Even Bernanke, whose Great Depression expertise usually pegs him as a dove, was particularly meticulous about describing the Fed’s stimulus-withdrawal tools this week, sending the bond market into a tailspin.

But with the unemployment rate rapidly climbing toward 10 percent — and expected to remain up there for the foreseeable future, some economists are telling Fed officials to hold their horses. Paul Krugman, in his blog, makes a vehement case for an ultra-dovish policy stance. He calculates that the ideal fed funds rate given current economic conditions should be, get this, -5.6 percent. In another post, he argues that even if the U.S. economic recovery is more robust than most believe, the Fed should still keep rates at rock-bottom lows for at least two years.

So where’s the case for monetary tightening? For some reason many Fed officials seem to view it as inherently unsound to stay at a zero rate for several years running — but I’m at a loss to understand what model, or even conceptual framework, leads them to that conclusion. One gets the impression of officials who have decided that they want to tighten, and are making up new conceptual frameworks on the fly to justify their desires.

Enter Thomas Pulley, economist at New America Foundation, who argues in the FT that a second Great Depression is still possible. He argues that continued deleveraging and an adverse feedback loop of rising joblessness and foreclosures will likely lead to a renewed contraction in economic activity.

There is a simple logic to why the economy will experience a second dip. That logic rests on the economics of deleveraging which inevitably produces a two-step correction. The first step has been worked through, and it triggered a financial crisis that caused the worst recession since the Great Depression. The second step has only just begun.