Economist David Harrington (spotted via Tyler Cowan's Marginal Revolution
) charges anti-plagiarism service Turnitin
with "playing both sides of the fence
, helping instructors identify plagiarists while helping plagiarists avoid detection." Turnitin analyzes student papers for suspicious elements in order to spot the plagiarism, scanning for things like lifted quotations or clever rephrasing. However, the same company offers a counterpart — a scanning service called WriteCheck which essentially lets the writer of a submitted paper know whether that paper would pass muster at Turnitin, and thus provides a way to skirt it (by tweaking and resubmitting). Harrington gave these two systems an interesting test, involving several New York Times articles and a book he suspected of having lifted content from those articles.