On August 2, 2010, Tim Geithner, the Treasury secretary, published an article defending the administration’s policies. In it he said, “The recession that began in late 2007 was extraordinarily severe. But the actions we took at its height to stimulate the economy helped arrest the free fall, preventing an even deeper collapse and putting the economy on the road to recovery.”

Which two of the three principles of economy-wide interaction are at work in this statement?