“What should be noted regarding (USA) / Japan’s experience is that the enthusiasm of market participants, together with the inconsistent projection of fundamentals, contributed to a large degree to maintaining temporarily high asset prices at that time. Such enthusiasm is often called euphoria, excessively optimistic but unfounded expectations for the long-term economic performance, lasting for several years before dissipating.”

“It was thus excessive optimism rather than consistent projection of fundamentals that mainly supported temporarily high asset prices.”

via Japan Iwato and Heisei stock and housing bubbles – How the U.S. is following in the path of Japan. Real estate lost decade, technology stock market bust, quantitative easing, and mania inducing monetary policy. » Dr. Housing Bubble Blog.