Reviewer 1's Review (Michael Cant)

“This paper presents a general game theoretical treatment of public goods games when the amount of public goods in question can depend both on the current and past frequency of cooperators in the population. Accordingly, this framework can be used to study the effect of variation in the durability of a public resource on the frequency of cooperation and on the rate at which goods are consumed. The model and analyses are very clearly explained and the paper is in general well written. The results are important and will be of general interest.

My main comment is that the 'message' of the paper about the effect of variation in durability is somewhat lost in the analyses, because the effect variation in c and u (which act as an index of durability) is not plotted explicitly in the figures, and the authors seem to spend disproportionate time on the more esoteric theoretical aspects of the model, such as the nature of the evolutionary dynamics. This is all fine, but I think that paper would be improved if the main results regarding durability were spelled out in a simple fashion, and perhaps the authors were to consider plotting their results with c (=u) along the abscissa, to make explicit the effect of variation in good durability. This would, I think, increase the penetration of the paper to non-theorists, which is important given the broad relevance of the results.”

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.