What is the mechanism of population transition in northwest European countries?

High fertility rate and low mortality rate, high immigration rate.

1. High fertility and low mortality: Northwest European countries have adopted a series of policies and measures to promote high fertility and reduce mortality. They provide a lot of social welfare and medical security, so that pregnant women and children are well cared for and protected. Secondly, they have invested in a good education system and medical care system to provide high-quality education and medical services, thus reducing mortality and prolonging life expectancy.

2. High migration rate: Northwest European countries also played an important role in the demographic transition because of their high migration rate. These countries attract a large number of immigrants with their high-quality education and employment opportunities, high-quality life and social welfare, which have made important contributions to the population growth of northwest European countries and played an important role in the labor market.