Upton Sinclair is also responsible for something else that passes without notice in our lives: the way we use shirt collars to talk about class. About fifteen years after publishing The Jungle, Sinclair wrote "The Brass Check," which was a muckraking expose on American newsrooms. In it, he described the office clerks upstairs as wearing white collar dress shirts, while the people in the mailroom below as wearing blue collar button-ups. This taxonomic shorthand — white collar vs blue collar — would become a popular way for writers to sidestep the uncomfortable discussion of class throughout the 20th century. Sinclair suggested that the ability to wear a white dress shirt allowed office clerks and middle managers to see themselves as socially distinct from laborers, even if they shared similar interests. An excerpt: "It is a fact with which every union workingman is familiar, that his most bitter despisers are the petty underlings of the business world, the poor office-clerks, who are often the worst exploited of proletarians, but who, because they are allowed to wear a white collar and to work in the office with the boss, regard themselves as members of the capitalist class." Of course, there were other dynamics at the time, such as race, but this taxonomic device (white collar, blue collar) continues to be popular today, especially in a post-industrial economy.