If a country's population suddenly increases because of immigration, what will happen to wages?

From a microscopic point of view, the more people are employed, the more competition there will be, the more choices employers will have, and the wages will naturally fall. From a macro point of view, more workers and faster economic development are still good for everyone, that is, the demographic dividend. However, immigration also involves many other specific issues. For example, investment immigrants generally increase employment opportunities, while skilled immigrants restrict industries. These industries are badly needed by the country, and there are no suitable people in China. Generally, it will not affect the income of local people and crowd out local employment opportunities. Therefore, generally speaking, there should be no direct connection between immigration policy and wages.