The United States is a nation of immigrants. Yet, despite their history and a culture of

immigration, Americans have mixed feelings about whether the country should keep welcoming them. Immigrant workers can either be substitutes for native-born workers or complements to them. When immigrant workers are substitutes for native-born workers, they compete for similar jobs. However, when workers are complementary, an increase in immigrant labor can increase job opportunities and wages for native-born workers.

Are immigrant workers substitutes or complements to native born workers in the United States? Explain why and cite your source carefully (at least one source is expected).