I recently found Joel E. Cohen and Christopher Small's work on hypsographic demography, i.e. the distribution of human population with altitude.
Does anyone know of any other research in this area? I am looking for ideas on how to visualize the relationship between elevation and population in a map and would like to see what has been done already. I could not find any maps beyond those created by Cohen and Small.
Not specifically demographic mapping, but the UN Food and Agricultural Organization folks have produced a number of publications with mappings at a world scale. The 2003 Environment and Natural Resources Working Paper No. 10 - "Towards a GIS-based analysis of mountain environments and populations" (B. Huddleston, E. Ataman, L Fe d'Ostiani)) may have some useful cartography for you.
Chapters are available as low resolution PDF from this FAO ftp site.
Also, seems like any human demographic mapping would mimic any general ecological range and habitat mappings that include elevation as a variable--seems you should be able to find a rich sampling of analogous cartography there.
You can find a series of papers with Google Scholar
Interesting article. It would be interesting (and not much work) to split up a graph like http://www.ldeo.columbia.edu/~small/Pop/HypsoDemo/Density.html based on the latitude. I'm quite sure that near the equator the density will be higher in upland areas (eg Ethiopia, Rwanda), wheareas further from the equator density is highest in lowland areas (Holland, Bangladesh,...)
