Determinants of wealth effect

Since the prosperity of so many countries benefits from immigration, why do more and more countries impose heavy restrictions on immigration? Because immigration is not only the creator of wealth, but also the consumer of wealth, and it will also have an impact on the resources, environment, infrastructure and employment of immigrant countries. The popularity of immigrants depends on the following aspects:

First, if an immigrant's wealth creation ability is greater than his wealth consumption ability, then we can call him a provider of product surplus, that is, a net contributor to regional wealth. On the contrary, immigrants are net consumers of wealth in the places where they move-only when the country faces insufficient demand and immigrants carry enough monetary assets can the migration of net consumers of wealth be beneficial.

Second, even the supplier of surplus products depends on whether the productivity of these new immigrants is higher than the marginal productivity of the people who moved in, and the bearing capacity of the environment and infrastructure.

If the expected labor productivity of new immigrants is greater than their consumption capacity and lower than the marginal productivity of the population in the immigrant area, then the wealth effect of immigrants is to increase the total wealth of the area, but it will reduce the per capita wealth of the area.

If the migrant population cannot find jobs quickly in a short time, or exceeds the carrying capacity of the urban environment and infrastructure, the quality of life of the original residents will be reduced.

In addition, developed countries will restrict many immigrants. Even if they can find employment opportunities, they will not exceed the capacity of the environment and infrastructure, nor will they reduce the per capita wealth of the places where they move. The reason is that immigrants may compete with local residents for employment opportunities and natural resources, reduce average wages and so on.