Here is a post at Future Pundit which seems to confirm what Irving Fisher, Robert Schiller, and Raj are noting 
 
Wishful Bettors Draw Others Into Dubious Investment Choices 
 
Overly optimistic people end up drawing more knowledgeable investors into unwise investment positions. 
 
"AUSTIN, Texas?Wishful bettors, those who make overly optimistic investments, will ultimately harm themselves financially, but they can harm entire markets as well, new research shows. 
 
In the paper, "Contagion of Wishful Thinking in Markets," researchers from The University of Texas at Austin and Cornell University demonstrate how wishful betting can contaminate beliefs throughout markets, as other market participants infer wishful bettors possess more favorable information than they do. As a consequence, investors who initially held accurate beliefs become overly optimistic about stock values. The research will be published in a forthcoming issue of Management Science. 
 
"The findings of our studies contradict what many people assume about markets, that wishful thinkers will be identified and disciplined by more sophisticated investors," said Nicholas Seybert, an assistant professor of finance at the McCombs School of Business at The University of Texas at Austin. "Instead, investors fail to recognize the existence of wishful betting even though most of them do it. As a result, wishful thinking can be contagious in financial markets."  
 
Over the years I've gradually dialed down in my mind my assumptions about the levels of competence in others in higher status positions. One of the biggest mistakes to avoid: just because someone is very competent about topic A that does not mean when they make equally confident statements about topic B that they have a clue as to what they are talking about. So many experts do not realize how ignorant they are outside of their areas of real expertise. 
 
People expect others must know better what they are doing. I think we are all looking for leaders to follow. 
 
Investors started with a short position in half of the stocks and a long position in the other half. The researchers reasoned that investors in short positions would desire low stock values, while those in long positions would desire high stock values. Despite all investors' initially holding unbiased beliefs about intrinsic stock values, those in short positions sold too many shares and those in long positions purchased too many shares. More surprisingly, investors did not anticipate this wishful betting behavior on the part of others. Even though they themselves purchased or sold too many shares of stock, they believed that other investors' trades were based on fundamental information about intrinsic value. By the end of trade, market prices were too extreme and the average investor appeared to be a "wishful thinker" ? holding
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