it was possible that nafta would encourage mexican citizens to stay in their country since their manufacturing work could still reach the american market easily. but since the creation of nafta, illegal immigration between mexico and the united states has only gotten worse. over the 10-year period between 1990 and 2000, the number of illegal immigrants per year doubled, or increased two times, despite the creation of nafta in 1994, according to thomas net industry market trends. nafta not being more effective in preventing the immigration crisis is a disadvantage to the agreement.