The Trump administration put a temporary freeze on new foreign workers that come here through the H-1B visa program. The administration argues that if the U.S. stops the flow of immigrants, there will be more jobs left for Americans in this recession. But researchers say the policy may backfire, because when immigrants go to a new country, they frequently bring new ideas, start companies and attract new investment money. Molly Wood speaks with Zeke Hernandez, a professor of global strategy at the University of Pennsylvania’s Wharton School.