The authors here are worth noting: Katz and Krueger are well known for publishing this[1] paper as well, which was one of the leading papers behind the idea that wage differentials are a function of skill-biased technology growth--that is, that automation and technology favors high skill workers and devalues low skill workers. This was an early paper that at least partially predicted the rise of wage inequality over the last decade where only high skill, high value jobs have really improved in wage growth, while low skill wages have stagnated.<p>[1] <a href="http:&#x2F;&#x2F;economics.mit.edu&#x2F;files&#x2F;563" rel="nofollow">http:&#x2F;&#x2F;economics.mit.edu&#x2F;files&#x2F;563</a>