Book excerpt: Using data from the U.S. censuses and American Community Surveys from 1950 to 2010, my dissertation investigates immigrants’ socio-economic integration in the U.S. I aim to study the causes and consequences of immigrants’ integration in the U.S. and to offer insights on policies that could facilitate immigrants in their assimilation process. The first chapter analyzes the increasing native-immigrant wage gaps since the 1980s. The second chapter studies the increasing wage premiums of intermarried immigrants since the 1980s. The third chapter studies why people live in ethnic enclaves. I find that technological change and globalization, which have increased the relative price of U.S.-specific social-communication and managerial skills since the 1980s, are important drivers of the widening wage gaps between natives and immigrants as well as the increasing wage premiums of intermarried immigrants. I also find that ethnic enclaves have a â€pulling†effect whereby immigration inflows to cities can simultaneously attract co-ethnic natives already living in the receiving cities to remain and entice co-ethnic natives living outside of the receiving cities to migrate in. I also find that this pulling effect is not due to potential monetary benefits in the labor market but is instead likely due to the lower housing prices and non-monetary benefits such as language convenience and ethnic amenities.