Most developed economies have some illegal immigrants. The United States has the largest number, with between 10 to 11 million. Without legal US identification (ID) documents, they cannot open bank accounts or buy houses. Many US firms have targeted this population, accepting the ID issued by their native countries and selling them products and services. Some Americans are furious with these business practices. Other Americans suggest that illegal immigrants represent a growth engine in an economy with relatively little growth elsewhere. How would you participate in this debate?