Ricerc@Sapienza

A comparative analysis of population dynamics worldwide contributes to profile distinctive demographic
and economic trajectories of urban growth, discriminating processes of settlement concentration
or dispersion under sequential cycles of urbanization. However, a wide-ranging
characterization of urban cycles based on demographic dynamics worldwide is still missing. The
present work is aimed at filling such a gap analysing long-term changes (1950–2030) in annual
population growth rate of 1691 urban agglomerations with more than 300,000 inhabitants in 74
world countries. Results of this study indicate that metropolitan growth worldwide was associated
with largely variable rates of population growth, highly positive before 2000 and progressively
reducing over recent decades. Despite important differences at continental (and country) scale,
demographic expansion of urban agglomerations showed two contrasting phases with a break
point in the 1980s denoting a progressive reduction in spatial heterogeneity of population growth
rates and a moderate slowdown in demographic dynamics. Intensity of urban expansion and
spatial heterogeneity in population growth rates across metropolitan agglomerations evidences a
trade-off between fast and slow demographic dynamics. These findings can be better understood
to support theories of sequential city growth, making a suitable contribution to policy making,
especially in countries where urban population is expanding more rapidly.