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International Journal of
Population Studies The use of multiregional life tables in Italy

of the population and, on the other, the population the Italian population during the period 2002 – 2013 was
follows the rules of the Markov chain model (Ledent, necessary(for a detailed overview of the applied procedure,

1980). In other words, the transition from one state to see: Buonomo & Strozza, 2020). The period chosen for
the next, by the observed population, depends only on reference ranges from January 01, 2002, to January 01,
the immediately preceding state (in our case survivorship 2013. We divided this period into four triennials (2002
and migration) and no account is taken of the history that – 2004, 2005 – 2007, 2008 – 2010, and 2011 – 2013) and
determined it. Another important element to consider is focused on macroregions (northwest, northeast, center, and
that multiregional life tables are built for contemporaries south, Figure 1) with respect to both residence and place of
(Rogers, 1995). Indeed, a longitudinal approach would birth. This aggregation assured us that while dividing our
require a great deal of information with a huge number population and internal migration flows, apart from gender
of details that are, at present, rarely (if ever) provided and age, even by macroregion of birth, the frequencies
by the national statistical offices. Therefore, the kind obtained were strong enough to ensure statistically valid
of information used to construct such tables plays a results. It also confirmed that flows between macroregions
crucial role. Ordinary multiregional tables, however, were never equal to zero. We chose single years of age and
are characterized by a strong element of approximation; decided to create an open-ended class (70 years old and
they are developed based on the place of residence of the more) to obtain the highest possible adherence to the data
population (and not the place of birth). In addition, the released by official Istat statistics. After obtaining the distinct
starting cohort of the traditional table is considered a birth population by macroregion of birth, it was possible to move
cohort although it is created without using information to the multiregional table using Rogers’ suggested formulas.
on the place of birth of individuals (Willekens & Rogers, In our annotations, we use “i” to indicate the macroregion of
1978; Rogers, 1995). Yet, as has been widely demonstrated, origin and “j” the macroregion of destination of the internal
the propensity to migrate depends on the place of birth of migration flows (we place the age in brackets on the right side
the individuals (Long & Hansen, 1975) and, therefore, it is of the capital letter, like in Rogers’ [1995] annotations). We
very important to take this variable into account. always refer to “origin” to indicate the macroregion where

2.2. Building multiregional life table for Italy the migration flow starts; conversely, we use the locution
“place of birth” to indicate where individuals are born. In
The multiregional table built in this study is defined as other words, we never use the term “origin” to indicate the
the “place-of-birth-dependent approach” (Ledent, 1980; birthplace.
Rogers, 2015), which creates tables distinguishable from
those built through the traditional approach based only It is important to recall that in Rogers’ (1973;
on the place of residence (the place-of-birth-independent 2015) multiregional model, international migrations
approach). In Italy, life tables are built precisely through simultaneously act as both disturbing and competing
the traditional method based on the location of residence events. Therefore, in the denominators of multiregional
while neglecting the place of birth (Bertino et al., 2015). probability formula, there are no international migrations.
This instrument is largely used to make demographic In other words, this approach only indirectly considers
forecasts in national official statistics (Italian National international migrants because they are included in the
Institute of Statistics [Istat], 2017). However, official Italian population considered and they can engage in internal
statistics do not provide data about the resident population migrations as well. According to Rogers (1973), these limits
classified by place of birth. It should be noted that such do not have a significant effect on the construction of the
data are available only in the years of the census. The aim number of years of life expectancies in other macroregions
of this research is to investigate internal migration using or on in the interpretation of results.
the multiregional model of the place-of-birth-dependent The first operation required to calculate the multiregional
approach. The multiregional life table requires the table was the determination of mortality and emigration
availability of stock data on the resident population and rates by age. We calculated the specific mortality rates ( m )
b
i
flow data, particularly births, deaths, immigration, and for the origin of each migration flow (i), sex (s), age (x) and
emigration both inside and outside the country. macroregion of birth (b), and for each of the four triennials
In our application, the multiregional life table takes (t). The annotation “i” represents both the macroregion of
the place of birth of both the resident population and the origin of the emigration and the place of residence of the
migratory flows into account. However, as mentioned above, population considered. In other words, we considered the
Istat only provides data of the population by region of birth macroregion of residence (r) equal to the macroregion of
in the census years (in our reference period, 2001 and 2011). origin of internal emigration (i); therefore, r = i. We also
Therefore, a preliminary allocation of the region of birth to measured the specific emigration rate by age (x), origin (i),

Volume 10 Issue 3 (2024) 5 https://doi.org/10.36922/ijps.1898