Page 8 - IJPS-9-1

International Journal of
Population Studies Local population changes as a spatial varying multiscale process

the process of demographic change in Italy from a spatial shown. The final section draws some conclusions and
perspective already exist, they usually address a rather future developments.
large geographic scale. A few studies that have referred to
a local scale (i.e., at municipality level) have used mainly 2. Data and methods
explorative approaches. The rare cases that have used a In the paper, we modeled the yearly average total population
regression approach are mainly based on a-spatial models growth rate (TOTPGR) by means of MGWR in function
or, at most, spatial global models (i.e., spatial autoregressive of a set of pure demographic determinants (independent
models). In other words, there is a lack of local multiscale variables).
approach in studying demographic changes in Italy.
These are:
To fill this gap, and based on these premises, this paper
proposes a study on population change at the local level • Yearly average natural population growth rate
(municipality) using a multiscale approach: Multiscale (NATPGR),
geographically weighted regression (MGWR hereafter) • Yearly average internal migratory population growth
recently proposed by Oshan et al. (2019). This class of rate (MIGPGR),
model has been recently used in several studies regarding • Yearly average international migratory population
different issues like COVID-19 fully vaccinated rates (Yang growth rate (INTPGR),
et al., 2022a), opioid use disorders in older populations • Yearly average of Italian population growth rate
(Yang et al., 2022b), and mortality (Cupido et al., 2021; • (ITAPGR), and
Yearly average of foreign population growth rate
Song et al., 2021) and has proved to be extremely useful to (FORPGR).
grasp the multiscale nature of population spatial processes.
However, quite surprisingly, to the best of our knowledge, The variables refer to the Italian municipalities
no application to Italy has been made. This is paradoxical if (7,904 cases) and cover the period 2011 – 2019. They have
we bear in mind that the demographic and socio-economic been standardized to a Z distribution so that their mean is
processes in Italy are deeply interested in spatial divides equal to zero (μ = 0) and their standard deviation is equal
and spatial dependence processes (Benassi & Naccarato, to one (σ = 1).
2017; Reynaud & Miccoli, 2018; Reynaud et al., 2018; In the analysis and the interpretation of the multiscale
Caltabiano et al., 2019; Zambon et al., 2020). Indeed, on regression results, we follow the approach of Yang et al.
a local scale, the heterogeneity of demographic dynamics (2022a; 2022b) in which three multiscale dimensions of
increases significantly, especially with regards to the drivers spatial process are defined:
of changes. Migrations (both internal and international)
play a key role in such changes since the natural growth • Level of influence, the percentage of population
is negative (or at most equal to zero) almost everywhere. affected by a certain determinant across the entire area;
The determinants of the capacity of a municipality to • Scalability, the spatial process of a determinant into
attract people (both from other Italian municipalities global, regional, and local process; and
and/or abroad) are many: Spanning from the opportunity • Specificity, the determinant that has the strongest
of finding a job, which is typically higher in urban areas association with the yearly average total population
located in the north and the center part of Italy, to the growth rate.
level of accessibility to services and infrastructures, which These dimensions are evaluated in relation to each
remains nowadays very low in many areas of the country, independent variable (Key findings section).
especially, mountainous and inland areas, and from many Population data used are based on the intercensal
other factors related for example the presence of certain reconstruction of resident population and are provided by
services (in particular primary school) that had proven to the Italian National Institute of Statistics (Istat). Basically,
be crucial to counteract depopulation processes (Benassi they refer to stocks (resident population at a given time)
et al., 2021; 2023). and flows (births, deaths, emigrations, and immigrations

The main goals of the paper are straightforward: (i) occurred in a given period) of resident population (Italians
Identifying what demographic determinants govern the and foreigners). The period refers to 2011 – 2019.
process of local population change in Italy; (ii) verifying if The local dimension of the study lies both in the
these determinants are spatially constant or not; and (iii) if regression approach used (MGWR, that is a local
their effects vary at different geographical scale.
regression approach) and, therefore, in the statistical
The paper is structured as follows: In the next section, units adopted. Indeed, our statistical units are the Italian
data and methods are described, and then results are municipalities. Municipalities, local administrative units

Volume 9 Issue 1 (2023) 2 https://doi.org/10.36922/ijps.393