As the quotations presented in the front matter of this book show, the international mobility of people is a controversial issue, with attitudes ranging from openness and tolerance toward immigrants in good economic times, to reluctance and even xenophobia and resentment, particularly during times of economic slowdowns, unemployment, and financial insecurity such as the one we live in now after the financial crash of 2008–09. From the late 19th century to the mid-20th century, international migration was an important engine for economic growth in such destination countries as the United States, Canada, Argentina, Australia, Brazil, and New Zealand – the so-called New World countries. Most of the immigrants to the New World came from Europe, particularly from Ireland, Italy, Spain, Poland, and Scandinavia, and from Asian nations (although the Chinese were often restricted). In the early 21st century, the geographic landscape of origin and destination countries for international migrants has changed fundamentally. In the last 20 years or so, due to their higher living standards and new economic opportunities (albeit moderate or partially reversed by the financial crisis of 2008–09), Ireland, Spain, Italy, and the Scandinavian and some Asian countries have turned from being, historically, net emigration countries to net recipient countries. These immigrants come from Latin America, Asia, Africa, Eastern Europe, and Russia – countries and regions that, at different points in time, have suffered economic and financial crises and political turmoil, and whose people seek, in foreign countries, more economic opportunities and stability for themselves and their families that are elusive at home.