How do illegal immigrants contribute to the US?

How do illegal immigrants contribute to the US?
The idea to answering that question is in Economics. Actually, the important concept is not about illegal immigrants contributing to the US, it's about how illegal immigrants from another country can contribute to any country. For example, illegal immigrants can contribute to US, and in another country like Malaysia, illegal immigrants can also contribute to that country. For this answer however, I shall refrain myself from using the word 'illegal', and just describe them as immigrants. Since I am not very familiar with the US industry, I shall use the example of Malaysia. In Malaysia, most immigrants are working in construction industries, some of them are working as maids, and also other areas of industry in which the pay is lower. Immigrants can contribute to the economy, as it is cheaper to hire them, then to employ our own people living in Malaysia. For example, many immigrants come to Malaysia to work as a maid. It's impossible to hire another Malaysian to work as a maid. They will never work in this area, as the pay is too low. Apart from that, Malaysians are better off doing something else, as the low pay doesn't match the skills they have. This means that if they do take the job, there is a mismatch between skills and pay. For example, a doctor will never work as a maid, or an engineer will never work as a waiter. On the other hand, for the immigrants, they are satisfied with the low pay, and also sometimes poor working environement or poor treatment, as to compare with what they can get back in their country, the low pay or poor working environment is nothing. Hence, immigrants will normally fill in the employment positions in a country in which they have comparative advantage in. While the countries own citizen will need to move up the career ladder or industry ladder to focus on other industries. Hence, immigrants help any country to fill in positions, which is too costly to hire the locals and also in industries where these immigrants have advantage in doing it. The economy can benefit from these immigrants a lot. In Malaysia for example, immigrants are mainly involved in constructions. Hence many building and roads are built with their involvement in it. However there can be some difficulties with immigrants in a country, in Malaysia for example, crime rates are often associated with immigrants coming in illegally. While in US, immigrants are often associated with the idea that they are robbing jobs from the locals. The important thing to understand is that, it's not immigrants that are robbing the job, it's just cheaper to hire them. In business who wouldn't hire someone with a lower pay right ? Anyone should be aware that workers that can perform the same job, with a lower cost will definitely have more chance to be hired in these global and free market. Hope this helps.