ABSTRACT
Two of the momentous changes that have occurred across much of the world over the last 200 years have been demographic: transitions to societies of low fertility and mortality (the demographic transition sensu strictu) and transitions to societies where a large majority of the population is concentrated in urban areas (the urban transition). These two transitions are not independent of each other, but neither are they associated in any neat or systematic way. Nevertheless, no highly urbanized society has high levels of fertility or mortality. One of the characteristics of these transitions is that, although the speeds, the dates of onset and the starting levels of the variables of the transitions have all been different, the overall trend, irrespective of political system or culture area, has been a shift towards lower fertility and mortality and an increasing concentration of population in urban areas.
