30.media.tumblr.com/tumblr_lyoxmeSk6x1qfa5xpo1_500.png www.tumblr.com/photo/1280/truth-has-a-liberal-bias/16870801588/1/tumblr_lyoxmeSk6x1qfa5xp Unions, Norms, and the Rise in American Wage Inequality http://www.wjh.harvard.edu/soc/faculty/western/pdfs/Unions_Norms_and_Wage_Inequality.pdf