WASHINGTON — One in seven Mexican workers have left their country and are working in the United States, an immigration study said on Tuesday. There were more than 7 million workers from Mexico in the U.S. labor force this year, 2 million more than six years ago, said the report’s author, Jeanne Batalova of the Migration Policy Institute, a Washington think tank. Batalova said the increase in numbers had to do with economic reasons, with more immigrants looking for a better life in the United States, but also with the increased enforcement at the U.S.-Mexican border. ‘It became more dangerous to cross the border, and that caused a ‘lock in’ effect,’ Batalova told Reuters in a telephone interview. Up to 9.4 percent of the all persons born in Mexico were living in the United States in 2005, according to the report. In the same year, 14 percent of Mexican workers had jobs on U.S. soil, compared to 2.5 percent of Canadians. Based on data from the Census Bureau 2006 Current Population Survey, Batalova found that Mexicans accounted for nearly one-third of the 22.6 million foreign-born workers in the United States, or almost 5 percent of […]