This question is prompted by visits to a number of smaller (in terms of population) countries in the past year or two: what counts as a saturation point for a country in terms of having enough universities? To focus the question, consider only those universities - call them research universities - which can award PhDs, and actually do so on a regular basis. Of course universities differ in size, but still, based on nothing more than a few alcohol-fuelled conversations with philosophers from Estonia, Denmark, Norway, Ireland, Croatia, Hungary, Israel and Portugal, here is my thesis: a country is unlikely to be able to sustain much more than one research university for each million of its population.
By this calculation the US should have about 275 research universities, the UK about 60, Canada 30, and Australia 20. You can check out the populations of the countries of the world here. I don't know how to check how many PhD awarding institutions there are in different countries. The figures work out reasonably well for the UK. There are more than 60 universities, but some of these barely have a research mission. Canada and Australia can't be too far off. As for the US, is 275 a reasonable estimate of the number of research universities?
Of course there are many developing countries which have nothing like one university per million. But I'm interested to know whether this is a reasonable maximum. Are there countries which manage to have more than (roughly) one PhD awarding institution per million? And has there been any discussion of this question?