Teachers in the nation's third-largest school district went on strike Monday. Duke University professor Jacob Vigdor, who researches teacher labor markets and merit pay, is available to comment on the strike.Jacob VigdorProfessor of public policy and economics, Sanford School of Public Policy, Duke University email@example.com://fds.duke.edu/db/Sanford/jacob.vigdorVigdor researches educational achievement, teacher labor markets and merit pay, college admissions policies, racial inequality and immigration policy. Quotes:"The teachers' strike is not your traditional union-management conflict. Wages aren't the primary issue. Instead, the heart of the battle concerns the method by which teachers are evaluated. The city of Chicago is caught between the Illinois State Legislature -- which passed a law mandating the use of test scores to evaluate teachers two years ago -- and the teachers who are hesitant to accept this kind of evaluation.""The animosity between teachers' unions and government -- even the Obama administration, which has pressed for more stringent teacher evaluations itself -- has been no secret over the past few years. The Chicago teachers' strike may in fact be the first open battle in a protracted war. The most sensible route to peace -- improving teachers' pay and working conditions to acknowledge that we expect more from them now -- is blocked, thanks to the effects of a weak economy on state and local governments."