Knowing Imagination

Deepak Chopra, in the San Francisco Chronicle, writes about the current crisis in the U.S. economy and the influence of the "nocebo effect", the opposite of the "placebo effect".  With the placebo effect people are inclined to positive reactions and outcomes because they are led to believe in the efficacy of a treatment. In the nocebo effect people are inclined to negative reactions and outcomes because they are led to believe in a negative way. Both placebo and nocebo effects can be understood as evidence of the power of the imagination. How much does the imagination effect the attitudes and choices of the U.S. public toward the economy?