A study of census data concludes that recent immigrants were critical to the nation's economic growth in the past decade, accounting for half the new wage-earners who joined the labor force in those years. The effect was particularly large among men: Eight of 10 new male workers in the previous decade were immigrants who arrived during that time, according to the report by the Center for Labor Market Studies at Northeastern University. The Northeastern University report, scheduled for release this week, offers powerful evidence of the growing impact of immigrants in American society. Earlier data from the 2000 Census showed...