First of all, we can consider why these people are prohibited from entering the country. Considering this problem, we can think about why these people want to smuggle. We can compare some phenomena in Chinese history. In the last century, many people sneaked into Hongkong and Macau through some places along the coast of China. Some even swim directly.
The primary reason is the large economic gap between the two places. We should strive to turn bicycles into motorcycles. The other side's economy is developing well, and if we have more opportunities to go, we will risk our lives. But what will happen if these people come? Although it can fill some vacancies in manual work, it is helpful to economic growth to some extent. But these migrants have done these jobs, and there are fewer jobs for local people.
On the other hand, there is also the problem of social security. Foreigners with incomplete documents cannot live well because of their documents and economic level. Can only live in poor conditions, and even open up some places to sleep. In this way, the appearance of the city is still a trivial matter, not only the crime rate is easy to rise, but also indirectly affects housing prices. Real estate is very important to a city's economy. Too many people come here illegally, which will have an impact on the city's economic development.
In addition, medical care and transportation cannot be taken care of by people with incomplete documents. It is impossible to count these populations in the region, which also brings trouble to economic planning. So some places in Europe are not only illegal immigrants, but also legal immigrants.