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. 2012 Nov;82(3):158-69.
doi: 10.1016/j.tpb.2012.06.009. Epub 2012 Jul 8.

Minimizing the dependency ratio in a population with below-replacement fertility through immigration

C Simon  1 , A O Belyakov, G Feichtinger
Affiliations

Minimizing the dependency ratio in a population with below-replacement fertility through immigration

C Simon et al. Theor Popul Biol. 2012 Nov.

Abstract

Many industrialized countries face fertility rates below replacement level, combined with declining mortality especially in older ages. Consequently, the populations of these countries have started to age. One important indicator of age structures is the dependency ratio which is the ratio of the nonworking age population to the working age population. In this work we find the age-specific immigration profile that minimizes the dependency ratio in a stationary population with below-replacement fertility. It is assumed that the number of immigrants per age is limited. We consider two alternative policies. In the first one, we fix the total number of people who annually immigrate to a country. In the second one, we prescribe the size of the receiving country's population. For both cases we provide numerical results for the optimal immigration profile, for the resulting age structure of the population, as well as for the dependency ratio.

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Figures

Fig. 3.1
Fig. 3.1
Female mortality rate μ(a) (left, logarithmic scale) and fertility rate f(a) (right); Austria 2008.
Fig. 4.3
Fig. 4.3
The adjoint variable ξ˜(⋅) determining the optimal immigration for two separate age intervals Γ1 and Γ2 in two cases: (a) λ˜1>0 (left) and (b) λ˜1<0 (right).
Fig. 5.5
Fig. 5.5
The direct (dashed line), indirect (solid blue line) and total (solid black line) effect of an additional a-year-old. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
See this image and copyright information in PMC

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