Inc magazine (online) just published an article quantifying the costs of bad bosses and the horrifying number of them out there. Three out of four employees report that their boss is the worst part of their job. 65% say they would take a new boss over a pay raise. 
It takes an average of 22 months to recover from a bad boss.
30% slow down due to a bad boss. There is much more in the concentrated article. I recommend you go see The Real Productivity-Killer: Jerks (and it is worth waiting through their brief advertisement).
This is totally consistent with my personal experience and observations. With the exception of Hewlett Packard while Bill Hewlett and Dave Packard were still running it, a brief stint for a steel fabricator, and my 20+ years of self-employment, I have not worked for a well managed organization and have not had really good bosses. I have had MANY poor ones and a frightening percentage of awful ones. Many others I have talked with have had similar experience. Awful is far too common, and good far too rare.
Also very enlightening from this article is that 22 month recovery period from a bad boss and serious health risk. Wow! That is quite helpful in understanding myself as well as others. It brings up some advice:
1) If you are working under a bad boss, CHANGE. Whatever the cost, the long-term benefit will make it worthwhile.
2) Go easy on the person in recovery. They will improve gradually and steadily over time, given a good work environment. This applies to yourself as well as others.
