A fiscal stimulus allegory

A guy walks into the doctor's office with a splitting headache. The doctor prescribes him some painkillers, but wanting to save some money, the guy takes only half the dose. He goes back a week later and says "Doc, I've still got this splitting headache." The Doc says, well why don't you just take the full dose this time. "The painkillers didn't work last time around," the guy responds, "why don't you just hit me over the head with a hammer instead?"