From an article by myself and Jeffry Frieden in the newly released Foreign Policy:
[We need] inflation — just enough to reduce the debt burden to more manageable levels, which probably means in the 4 to 6 percent range for several years. The Fed could accomplish this by adopting a flexible inflation target, one pegged to the rate of unemployment. Chicago Fed President Charles Evans has proposed something very similar, a policy that would keep the Fed funds rate near zero and supplemented with other quantitative measures as long as unemployment remained above 7 percent or inflation stayed below 3 percent. Making the unemployment target explicit would also serve to constrain inflationary expectations: As the unemployment rate fell, the inflation target would fall with it.