Replacement migration

In demography, replacement migration is a theory of migration needed for a region to achieve a particular objective (demographic, economic or social). In most cases in which replacement migration has been implemented, it is to prevent a decline in the working population of a country and to keep the total population growing. Often, these overall declines in the population are influenced by low fertility rates. When fertility is lower than the replacement level of 2.1 children per woman and there is a longer life expectancy, this changes the age structure over time. Overall, the population will start to decline as there will not be enough children born to replace the population of people lost and the proportion of older individuals composing the population will continue to increase. One concern from this is that the age-dependency ratio will be affected, as the working-age population will have more dependents in older age to support. Therefore, replacement migration has been a proposed mechanism to try and combat declining population size, aging populations and help replenish the number of people in the working age groups. Projections calculating migration replacement are primarily demographics and theoretical exercises and not forecasts or recommendations.…

In demography, replacement migration is a theory of migration needed for a region to achieve a particular objective (demographic, economic or social). In most cases in which replacement migration has been implemented, it is to prevent a decline in the working population of a country and to keep the total population growing. Often, these overall declines in the population are influenced by low fertility rates. When fertility is lower than the replacement level of 2.1 children per woman and there is a longer life expectancy, this changes the age structure over time. Overall, the population will start to decline as there will not be enough children born to replace the population of people lost and the proportion of older individuals composing the population will continue to increase. One concern from this is that the age-dependency ratio will be affected, as the working-age population will have more dependents in older age to support. Therefore, replacement migration has been a proposed mechanism to try and combat declining population size, aging populations and help replenish the number of people in the working age groups. Projections calculating migration replacement are primarily demographics and theoretical exercises and not forecasts or recommendations. However, this demographic information can help prompt governments to facilitate replacement migration by making policy changes. The concept of replacement migration may vary according to the study and depending on the context in which it applies. It may be a number of annual immigrants, a net migration, an additional number of immigrants compared to a reference scenario, etc. Replacement with immigrants can have partisan motivations. R_{(t)}\ '=\frac{-\Delta P_{(t,t+1)} }{A_{(t)} } Where: R(t)' = Replacement Migration avoiding the decline of population in year t A(t) = retention rate of immigrants year t, defined by (1 - instantaneous departure rate) ∆P(t,t+1) = change in the total population in the time interval t, t+1 ===Constant replacement migration=== The constant replacement migration does not fluctuate and remains the same throughout the projection. For example, it will be calculated with a projection providing a migration of X throughout the temporal horizon. ==See also== Cultural sustainability Demographic engineering Human overpopulation Umvolkung

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