In an article posted on its website on Aug. 16, 2012, the Washington Examinerprovides some interesting data, garnered from the data unions are required to submit to the U.S. Department of Labor, regarding the compensation received by the leaders of some of America's largest unions. 

First, the average yearly compensation for the top 25 earning union leaders was approximately $570,000.00, a pay raise of about 88 percent on average from the year 2000. That rate of growth not only more than doubled the growth rate of the average union worker (38 percent), it also was counter to the trend of CEO compensation, which actually declined over the same period of time.  Additionally, the yearly compensation for these union leaders in 2011 was approximately ten times that of the average worker, who earned $53,463 in the private sector and $59,229 in the public sector. The article can be read in its entirety here.

P.S.  Yes that is correct, according to this article public sector workers make 10.8 percent more than private sector workers.