Endogenous Population Dynamics and Metropolitan Cycles: Long-Term Evidence from Athens, an Eternally Mediterranean City.

Natural population growth is an intrinsic property of demographic systems that depends on (spatially) non-stationary processes of fertility and mortality. Assuming distinctive demographic dynamics as a characteristic attribute of urban, suburban and rural systems, analysis of spatial variability in natural population growth delineates nonlinear stages of metropolitan expansion, possibly reflecting divergent responses to socioeconomic stimuli. The present study investigates endogenous population growth (1956-2019) and the relationship with demographic density as basic attributes of individual stages of the city life cycle in Athens (Greece), a mono-centric metropolitan region in Southern Europe. A spatially explicit analysis of natural balance rates at local scale identified two stages of growth, namely compact urbanization (mid-1950s to late 1970s)-with agglomeration strengthening the polarization in demographically dynamic and shrinking districts-and spatially decentralized suburbanization (early 1980s to late 2010s)-with a less defined role of agglomeration economies and more heterogeneous demographic processes. However, the impact of population density on endogenous growth was stronger in recent decades, suggesting how demographic dynamics may still respond to agglomeration stimuli, at least during recessions. At the same time, the spatial structure of natural balance rates became more mixed, likely reflecting the importance of heterogeneous demographic behaviors at the individual level.