In recent years, more than 1 million people a year have immigrated to the U.S., a level not seen since before the Great Depression. This boom is most apparent in the urban areas where immigrants tend to cluster. Given their numbers, these newly arrived residents must have some effect on local labor markets. Yet economists have been puzzled by the evidence that immigration has little impact on the wages and employment of native-born workers. So how great is immigration’s impact on local labor markets? Is it limited to markets where immigrants settle, or is it spread across the country? Ethan Lewis sifts through the theory and evidence to answer these questions.