| Chapter 1: | Introducing Japan’s Shrinking Regions* |
C: In-migration exceeds birth surplus
D: In-migration exceeds death surplus
Population decrease:
E: Death surplus exceeds in-migration
F: Death surplus exceeds out-migration
G: Out-migration exceeds death surplus
H: Out-migration exceeds birth surplus
Focusing on population decrease, types G and H represent the old type of depopulation, in which more people (usually young and with additional economic and reproductive capacity) leave than are replaced; types E and F representing the new pattern and are biological consequences of an ageing society.
These patterns usually do not occur in isolation as one-dimensional or unidirectional processes. For example, settlements with chronically low fertility rates but dynamic economies can be sustained by in-migration from surrounding areas—a type D pattern of population increase. This pattern, however, often ends when in-migration from areas with a birth surplus is no longer sufficient to outweigh the death surplus, thereby developing into an E pattern; what Bucher and Mai (2005, p. 15) referred to as the theory of ‘regional-demographic shift of phases.’ These two scenarios reflect the complexity of depopulation in particular. Moreover, patterns F and G reflect a demographic reality that is particularly devastating to rural areas, what might be referred to as a double-negative demographic disequilibrium (see Matanle & Sato, 2010), a situation in which both death and out-migration contribute simultaneously to shrinkage.
Beyond this demographic–migration dynamic, the shrinkage that takes place in rural locales is also a function of many interrelated, even mutually causative, factors. First and most notable is the loss of population due to natural decreases and out-migration (especially of younger people), which is both a cause and a consequence of demographic ageing and which results in reductions in a region’s stock of social and human capital. Out-migration is often due to a variety of factors, including a decline in the availability of desirable local jobs and a rise in unemployment, which