Replacement migration

In demography, replacement migration is the migration needed for a region to achieve a particular objective (demographic, economic or social).[1] Generally, studies using this concept have as an objective to avoid the decline of total population and the decline of the working-age population. Projections calculating migration replacement are primarily demographics and theoretical exercises and not forecasts or recommendations.

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,[2] a net migration,[3] an additional number of immigrants compared to a reference scenario,[4] etc.

Types of replacement migration

Replacement migration may take several forms because several scenarios of projections population can achieve the same aim. However, two forms predominate: minimal replacement migration and constant replacement migration.

Minimal replacement migration

Replacement migration is a minimum migration without surplus to achieve a chosen objective. This form of replacement migration may results in large fluctuations between periods. Its calculation will obviously depend on the chosen objective. For example, Marois (2008) calculates the gross number of immigrants needed to prevent total population decline in Quebec. The formula is then the following:

R_{(t)}\ '=\frac{-\Delta P_{(t,t+1)} }{A_{(t)} }

Where:

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.

Results

The raw results of replacement migration are not necessarily comparable depending on the type of replacement migration used by the author. Nevertheless, major demographics conclusions are recurrent:

Examples of results

Replacement migration to prevent the total population decline (annual average):

Replacement migration to prevent the decline of population of working age (annual average)

Criticism

Two reasons make replacement migration unnecessary. The first reason is that there is nothing inherently wrong with a declining population. Although countries with declining populations may suffer economic consequences, such populations can establish durable equilibriums with their environment. This is the theory of degrowth which promotes downscaling of production and consumption.

The second reason is that the receiving country stimulates women to give birth to more children. An increased fertility rate counters the need for replacement immigration.

Bibliography

http://circa.europa.eu/irc/dsis/jointestatunece/info/data/paper_Bijak.pdf

http://www.bibliotheque.assnat.qc.ca/01/mono/2007/10/949645.pdf

http://www.erudit.org/revue/cqd/2008/v37/n2/038132ar.pdf

http://www.osfi-bsif.gc.ca/app/DocRepository/1/fra/bac/pdf/2006_09_22_belanger_f.pdf

http://www.un.org/esa/population/publications/migration/execsumFrench.pdf

Notes and references

  1. http://www.erudit.org/revue/cqd/2008/v37/n2/038132ar.pdf
  2. http://www.bibliotheque.assnat.qc.ca/01/mono/2007/10/949645.pdf
  3. http://www.un.org/esa/population/publications/ReplMigED/migration.htm
  4. http://circa.europa.eu/irc/dsis/jointestatunece/info/data/paper_Bijak.pdf