Artículos con la etiqueta ‘Demografía’

Space-time correlations in urban sprawl

Por • 23 jun, 2013 • Category: Economía

Understanding demographic and migrational patterns constitutes a great challenge. Millions of individual decisions, motivated by economic, political, demographic, rational, and/or emotional reasons underlie the high complexity of demographic dynamics. Significant advances in quantitatively understanding such complexity have been registered in recent years, as those involving the growth of cities [Bettencourt LMA, Lobo J, Helbing D, Kuehnert C, West GB (2007) Growth,. Innovation, Scaling, and the Pace of Life in Cities, Proc Natl Acad Sci USA 104 (17) 7301-7306] but many fundamental issues still defy comprehension. We present here compelling empirical evidence of a high level of regularity regarding time and spatial correlations in urban sprawl, unraveling patterns about the inertia in the growth of cities and their interaction with each other.

Virtual water controlled demographic growth of nations

Por • 30 ene, 2013 • Category: Economía

Population growth is in general constrained by food production, which in turn depends on the access to water resources. At a country level, some populations use more water than they control because of their ability to import food and the virtual water required for its production. Here, we investigate the dependence of demographic growth on available water resources for exporting and importing nations. By quantifying the carrying capacity of nations based on calculations of the virtual water available through the food trade network, we point to the existence of a global water unbalance. We suggest that current export rates will not be maintained and consequently we question the long-run sustainability of the food trade system as a whole.

Tunisia’s lost generation

Por • 19 ene, 2011 • Category: Opinion

There is no practical way to interrupt the train wreck. Muslim countries that invest heavily in education, of which Tunisia is the best example, never achieve a critical mass of trained graduates. The main consequence of more education appears to be a plunge in fertility rates within a single generation, from the very large families associated with traditional society