The study, by economists Shushanik Hakobyan of the IMF and John McLaren at the University of Virginia, looks at changes in earnings among different populations of workers before and after NAFTA, which eliminated tariffs among the US, Mexico, and Canada. The authors of the study did not find large or significant changes in earnings for blue-collar married men after the trade pact was established. Among single people, of both genders, there was a drop in wages, but it was small and not always statistically significant. But no matter how they specified their model, wages for uneducated, married women tanked after NAFTA.