George Borjas formalized an econometric model to argue that these people are not necessarily positively self-selected. Ottaviano and Peri argued that these people are imperfect substitutes in the labor market, dampening their potential competitive effects. In a paper partially titled for inequality, David Card found that a supply shock caused (10[1])by these people had no negative impact on (10[2])wages (10[1])for low-skilled workers; (10[3])Card’s (-5[1])work focused on these people in Miami from the Mariel Boatlift. Geographers may divide these people’s motivations into “push” and “pull” factors. For 10 points, name these people contrasted with natives, who permanently relocate to a new country. ■END■ (10[1])