What are some positive and negative effects of migration?

Cons
Depression of wages may occur but this seems to be temporary.
Having workers willing to work for relatively low pay may allow employers to ignore productivity, training and innovation.
Migrants may be exploited.
Increases in population can put pressure on public services.
Unemployment may rise if there are unrestricted numbers of incomers.
There may be integration difficulties and friction with local people.Positive
Job vacancies and skills gaps can be filled.
Economic growth can be sustained.
Services to an ageing population can be maintained when there are insufficient young people locally.
The pension gap can be filled by the contributions of new young workers and they also pay taxes.
Pros
Job vacancies and skills gaps can be filled.
Economic growth can be sustained.
Services to an ageing population can be maintained when there are insufficient young people locally.
The pension gap can be filled by the contributions of new young workers and they also pay taxes.
Immigrants bring energy and innovation.
Host countries are enriched by cultural diversity.