This is my first post-Labor Day post, so we'll write about the subject that comes to mind. Desi Arnaz. It is a fact, to be condemned or welcomed at your leisure, that labor unions represent a shrinking portion of the labor market pie. Despite (or because of?) the protection of union activity in the private sector, the role of unions there has been in decline for decades. In the 1950s one in every three private sector employees was a member of a union. By 2011, only 6.9%, roughly one out of every 14 were union members. Here's a link for that 6.9% figure, in case fact checkers are reading. I think reporter Greenhouse rather buried his lede, though: that critical figure doesn't appear until the fifth paragraph . Anyway: some conservatives talk about this decline almost as if it is karma. Unions are, in their view, inherently suspect operations, and they are shrinking because of their own cosmic badness. I disagree. Further, I'd like to tell a stor...