Lawrence Summers writes in the Washington Post:
while there are enormous uncertainties, there is a chance that macroeconomic stimulus on a scale closer to World War II levels than normal recession levels will set off inflationary pressures of a kind we have not seen in a generation, with consequences for the value of the dollar and financial stability. This will be manageable if monetary and fiscal policy can be rapidly adjusted to address the problem. But given the commitments the Fed has made, administration officials' dismissal of even the possibility of inflation, and the difficulties in mobilizing congressional support for tax increases or spending cuts, there is the risk of inflation expectations rising sharply. Stimulus measures of the magnitude contemplated are steps into the unknown. For credibility, they need to be accompanied by clear statements that the consequences will be monitored closely and, if necessary, there will be the capacity and will to adjust policy quickly.