Explain the reasoning behind why employment could increase for domestic-born workers if immigrant workers become complementary resources rather than substitute resources.

Many immigrant workers and domestic-born workers are complementary resources rather than substitute resources. When that is the case, the lower wage rate resulting from large-scale immigration reduces production costs, creating an output effect that raises labor demand for certain domestic-born workers. For instance, the large number of immigrants in the home construction business lowers the cost of building homes, increasing the number of homes built. This results in an increased demand for domestic-born residents who produce home building supplies.