The economic cost of immigration has often been misunderstood in the rancorous, often emotional debate on the campaign trail. Generally speaking, immigration is a boon to the economy. That's because the nation's economic output, or gross domestic product, depends heavily on the number of workers and how productive they are. The more workers a country has, the more that economy is likely to produce. Also, immigrants in the U.S. start businesses at a higher rate than native-born Americans.