Harvard economist Greg Mankiw notes that President Obama's promise that the American Recovery and Reinvestment Act "will create or save 3.5 million jobs" is nonfalsifiable:
The expression "create or save," which has been used regularly by the President and his economic team, is an act of political genius. You can measure how many jobs are created between two points in time. But there is no way to measure how many jobs are saved. Even if things get much, much worse, the President can say that there would have been 4 million fewer jobs without the stimulus.
[via South Bend Seven]