Underpopulation, sometimes known as depopulation, refers to a population whose numbers are insufficient to maintain a viable economy. Sites whose topics focus on underpopulation are listed in this category.
 
 
Recommended Resources
A discussion of the problems of population decline is presented here, with references, and population facts listed by specific countries, the economic consequences of underpopulation, and national efforts to reverse declining populations.
http://medlibrary.org/medwiki/Underpopulation/
A definition of the term is supplied, as well as a discussion of the issues surrounding a declining population.
http://underpopulation-toomnyppl.blogspot.com/