For decades, you could always count on the Federal Reserve to pull the plug on prosperity too soon, seeing ghosts of inflation everywhere. The Fed, responsive as it was to creditors, preferred a dose of recession to any sort of price pressures, especially wage increases. That changed with the regimes of Fed chairmen Alan Greenspan and Ben Bernanke. Greenspan was willing to keep interest rates low because the banks kept getting into difficulty after bouts of speculative excess in the 1980s and '90s and needed the cheap money to rebuild their balance sheets. The ultimate such collapse occurred just five years ago this week, when the crash of Lehman Brothers revealed the rot in the entire system, and one over-leveraged domino after another fell. The Fed, after a somewhat anomalous run as the engine of recovery, seems to be reverting to type. Trouble is, the economy won't cooperate with this scenario. Inflation is nowhere to be seen, and the recovery continues to be weak.