Population, territory and sustainable development

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F. MIGRATION DRAW, SOCIODEMOGRAPHIC CHARACTERISTICS
AND STANDARD OF LIVING
Most public initiatives having to do with the system of cities operate within the logic of population size
categories. Policies and programmes are therefore designed to promote medium-sized cities, reduce the
pull of large ones and redirect migration flows to small cities, among other things (Rodríguez and Busso,
2009). The study in the previous section offers new evidence on the relationship between migration draw
and city size. Migration draw varies within each category, undermining the prevailing simplistic tendency
to assume homogeneity within each segment (large cities = problematic = migrant senders, versus small
and medium-sized cities = friendly = attractive).
The next section introduces more variables to explore this relationship in greater detail, using
statistical techniques to synthesize information and gain an understanding of the overall relationship
between standard of living, city size and migration draw.
The intercorrelation matrix in Table IX.7 is a first step in that direction. It was calculated on the
basis of all the cities for which socioeconomic (Millennium Development Goal proxies) and migration
data are available, which, as mentioned above, includes more than 1,439 cities in 14 countries. The
relevant coefficients for this purpose are in rows 18 and 19, which quantify the simple linear correlation
between the volume of total net internal migration and migration within the urban system, on the one
hand, and the demographic and socioeconomic attributes of the cities, on the other hand.
The main conclusions arising from total net migration coefficients are set out below.
(i) Cities offering better living standards tend to have a stronger draw, particularly those
offering more services and better information and communication technology infrastructure
and coverage. This supports the classic hypothesis that people move from places of origin
with inferior living conditions to destinations where they are better. Since the subject is total
net migration, the draw for a rural population might play an important role without this being
reflected in the coefficients, which only refer to standards of living in cities. 10
(ii) The relationship between city population size and migration draw (total or within the urban
system) that can be deduced from the tables with city-size segments fades into statistical
insignificance. This suggests that the “size effect” in the tables does not operate alone, but
rather through the relationships between size and living conditions that, as discussed in
section D, are still positive.
(iii) One dimension of the standard of living that does not have a statistically significant
relationship with total migration draw is unemployment. This collides with traditional
theories that put the search for work in the centre of the decision to migrate. Nonetheless, as
briefly discussed above, many factors may explain this apparent unrelatedness. These include
wages and income, since levels that rise with city size could be a stronger pull factor than the
availability of work. Problems of endogeneity are also evident, since unemployment can be
explained, at least partly, by migration (particularly, higher unemployment rates in areas
10
This reflects the mismatch between territories where the issue is migration (municipalities or comunas making
up a city or where there is a city with a population of 20,000 or more) and the territories referred to by standardof-living
indices, which are the urban areas within these municipalities.