Population size is important not only as an indication of overall capacities for production or demands on consumption. It is perhaps more important for its indication of the infrastructural demands to provide the services and resources needed to build human capital. Density is an important ecological variable related to carrying capacity. Asia has been and remains the most densely settled of our major world regions, despite large tracts of desert and sparsely settled land. Cities are points of exceptionally high density, but social scientists have typically found mixed results in the attempt to link density to urban problems, or to the quality of life. The Infant Mortality Rate or IMR is usually considered one of the single most sensitive indicators of the health and wellbeing of a population. Infant deaths are relatively easy to control, given an emphasis on primary health care and a rather simple technology to prevent infectious diseases.