How does migration typically influence population size?

Migration plays a significant role in shaping the dynamics of population size. The correct answer reflects the complexity of migration's impact, as it can indeed result in both increases and decreases in population size.

When people migrate into a region, this process is known as immigration, and it leads to an increase in the local population. Conversely, when individuals leave a particular area, this is termed emigration, which results in a decrease in that population. The net effect of migration on population size is therefore influenced by the balance between these two flows.

For instance, if a country experiences a high rate of immigration while simultaneously having low emigration rates, this can lead to substantial population growth. Conversely, if emigration rates are high and immigration rates are low, the population may decline.

This nuanced understanding highlights that migration is not a one-directional force but a complex interplay that can shape demographic trends in different ways depending on specific circumstances in each region.