Population, territory and sustainable development

127
urbanized; the rural population base that is the source of migration to the cities is still large in relative
terms, while the urban population base on the receiving end is not, so that the final effect on the
destination point is magnified. The Central American countries are examples, with the exception of
Nicaragua. In highly urbanized countries, however, the net rural-urban transfer tends to represent less
than 30% of urban population growth. Thus, the contribution of rural-urban transfer to the expansion of
the urban population can be expected to drop as the urbanization process advances. This trend is
illustrated in table VIII.2: the three countries for which 2010 census data are available record a substantial
drop in this factor as a driver of population growth, both male and female.
Obviously, this negative statistical relationship between the level of urbanization and the
weight of rural-urban transfer in urban population growth is not irreversible. If fertility rates continue to
fall in urban areas to the extent that they produce null or negative natural growth rates, and if net ruralurban
population transfer continues, its contribution to urban population growth could increase sharply
and significantly.
It bears repeating that the decreasing impact of rural-urban transfer on urban population growth in
no way invalidates the fact that this transfer continues to be the demographic explanation of the increase
in the urban percentage (urbanization).
Looking back to chapter IV, the fact that population transfer from rural to urban areas is
contributing less and less to urban population growth should not obscure the sustained and significant
impact it is having on rural population growth in the region, which has been stable or even negative for
decades. As with any average, this average stability masks opposing trends. In rural areas where the trend
is towards depopulation, the shift is concerning because it usually involves a loss or under-use of
resources (infrastructure, facilities, land) and can lead to food insecurity or even erosion of sovereignty in
border areas.
Rural-urban migration has an impact not only on population growth but also on population
composition in both areas. As seen in Chapter IV, the dependency ratio of the rural population is higher
because rural emigration is age-selective and mainly involves young working-age persons. The gender
composition of the rural population is also affected by migration selectivity. Rural emigration in Latin
America has generally been selective for females (although there are countries that follow a different
pattern), so it is not unusual for the sex ratio to be higher in the rural areas of the region.
The effects of rural-urban migration on the gender and age structure of rural and urban areas can be
estimated more precisely using the procedures described and employed in chapter V. These procedures,
however, can only be applied in a handful of countries whose censuses provide the necessary data for
making direct estimates of rural-urban migration, that is, for building rural-urban migration matrices. These
include Panama, whose 2010 census findings are presented in tables VIII.3, VIII.4 and VIII.5.
Table VIII.3 highlights the marked disparity in the gender composition of urban and rural areas. 9
The sex ratio for urban areas in 2010 was around 95, versus as much as 111 for rural areas. Rural-urban
migration in the 2005-2010 period widened the gap, reducing the ratio of males to females in the urban
population by 0.25% and increasing it by 1.1% in rural areas.
9
These figures are from an internal migration matrix for the 2005-2010 period. Some cases are therefore
excluded, such as children under the age of five, international migrants during the period and people who did not
answer some of the relevant questions (habitual place of residence, previous place of residence, duration of
residence). Even so, the matrix considers over 90% of the population covered by the census, so the indicators are
representative of the demographic reality of the two areas.