Page 27 - IJPS-9-1

International Journal of
Population Studies Population aging and immigration in Japan

evidence of immigration causing higher average rates of Foreign resident
unemployment.
population = f (Demographic condition,
1.2.4. Population by age group and dependency ratio non‑‑Demographic conditions) (I)
This section reviews the literature that links population by The functional Equation I states that foreign resident
age group and dependency ratios, as these demographic population is a function of demographic condition and
factors are examined in this study. In the late 20 century, non-demographic condition.
th
population composition became an issue for economic
growth. Horioka (1997) showed that the age structure of the Equation I can be extended to include the demographic
population had a substantial impact on economic growth and non-demographic factors previously identified in
in Japan. Similarly, Bloom & Williamson (1998), Lindh the literature. The growth equation of immigrants in
& Malmberg (1999), and Feyrer (2005) demonstrated this study is based on the Hatton & Williamson (1998)
that population composition by age group was related to model and the previous research reviewed herein. Thus,
economic growth in industrialized countries. a few modifications are added to their model. The main
difference from the Hatton & Williamson (1998) model is
Due to population aging, the youth and old-age that the net migration is replaced by the ratio of foreign
dependency ratio has been changing considerably. The resident population to the total population of Japanese
dependency ratio is defined as “the ratio of the number of nationals (F2J). The selections of the control variables are
persons in a given dependent age group of interest to the followed from the literature review as seen in the section
number in a different age group considered to contain those above.
persons providing support to those dependent” (Siegel & The regression Equation II of the model is:
Swanson, 2004, p. 758). Siegel & Swanson (2004) noted
that dependency ratios are a measure of the age structure △Foreign residents = b + b △X 1t–1 + b △X 2t–1
t
2
1
0
of a population. They relate the number of individuals that + b △X 3t–1 + e t (II)
3
are likely to be economically “dependent” on the support of Where △ is the annual percentage change in a variable,
others. Kogel (2005), using data from 70 countries for the which is the annual growth rate of a variable; X contains
1
period 1965 – 1990, observed that the youth dependency the ratio of population by age group to the total population,
was negatively related to total factor productivity growth, the youth dependency ratio or the old-age dependency
and he pointed out that age structure affected the most ratio; X contains the demographic condition represented
2
important determinant of international differences by the total fertility rate (TFR); and X contains the overall
3
in output per worker. The changes in the dependency economic condition represented by the unemployment
ratio are creating significant policy challenges in some rate and hourly earnings of manufacturing; t is the time
Asian countries (Ogawa, 2009). Therefore, including the index. The data set consists of annual series; thus, t–1
population composition by age group or dependency ratio suggests 1 year before present.
as an explanatory variable is important when examining The two main alternative hypotheses (H) are
immigration while a population is aging.
H : An increase in the population by age group is
To summarize, existing studies generally support 1 associated with an increase or a decrease in the
the hypothesis that a positive association exists between number of foreign residents.
population aging and immigration in industrialized H : An increase in the dependency ration is associated
countries. However, there remain uncertainties as to 2 with an increase or a decrease in the number of foreign
what age range population is considered to increase in residents.
the proportion of older people related to the positive
association, and how population composition by age group To test H and H , this study examines the independent
2
1
is related to the immigration in Japan. This study offers contribution of each age group and the dependency ratio
new evidence using a set of data on various age groups and to the change in the foreign resident population.
control variables in Japan for the period 1975 – 2019. 2. Data and methods
1.3. Research hypotheses 2.1. Data
Based on the evidence from previous research and The data consist of annual series for Japan for the period
literature presented above, the functional relationship can 1975 – 2019. All variables are quantitative with annual
be expressed as: average values measured by indices. The dependent

Volume 9 Issue 1 (2023) 21 https://doi.org/10.36922/ijps.407