Introduction: Migration is becoming a very important topic for the life of big cities. The educational, social, cultural and financial opportunities of large cities attract large numbers of people to large cities. Los Angeles is home to representatives from more than 140 countries who speak at least 224 different languages. Many people move there for a better quality of life and work. The city is second in the United States after Miami for the percentage of population born outside the country. So, there can be some advantages and disadvantages when immigrating to Los Angeles. Economic factors: The first negative effect is that this causes economic problems for the city. More importantly, migration leads to a decrease in the quality of workers. Immigrant workers are semi-skilled. Furthermore, the government suffers from the unpaid taxes of immigrants, illegal families. According to Michael's data, in the county's health system, illegal immigrants are treated at a cost of about $500 million per year. Furthermore, one in fifteen people in the city is an illegal immigrant: the state in a year...