Reviewer 1's Review

-----

This excellent manuscript describes how publicly available and partly free data sources were used to create relatively cheap but highly detailed settlement and population density maps of the East African region. In order to achieve this goal, the authors followed a well-conceived and pragmatic strategy. New and freely available tools such as Google Earth were used where appropriate, which makes sense not only for data acquisition and analysis, but also in terms of future data provision to the public. The resulting map appears to be of better detail and quality than any comparable existing map for the same area, and can indeed be useful for several purposes. It remains to hope that these will not remain limited to academic modelling and estimations, but actually contribute to equitable improvement of living standards.

The manuscript is written very clearly in most parts, with only the Methods section being a bit difficult to follow and confusing sometimes. Is it meant to be a step-by-step description? If so, this should be stated somewhere. Boiling down the Methods section in favour of the supplementary material would surely improve the paper in terms of clarity and understandability for non-specialists. In its current state, most of the information given in the supplementary text is already included in the main text, word by word, almost unabridged. By contrast, the supplementary figures really do add information.

The authors provide adequate proof for their claims, and treat the literature fairly. A large part of the referred articles are the authors' own work though, which makes sense as the study is a continuation of their previous work.

Unfortunately and unlike stated, the map is not yet available on the MAP website. Therefore it is not possible yet to judge its true quality and detail as well as potential descriptions related to the map that might be published on the website together with the map.

The statements made above as well as the list of remarks and small errors below only include minor revisions. These do not affect my overall recommendation, which is to accept the manuscript after those minor revisions are made.

-----

N.B. These are the general comments made by the reviewer when reviewing this paper in light of which the manuscript was revised. Specific points addressed during revision of the paper are not shown.