> did not have historical populations in mind when deciding on settlement and army sizes. European populations were not at all static. There were many massive

> did not have historical populations in mind when deciding on settlement and army sizes. European populations were not at all static. There were many massive population declines more or less going back to the beginning of agriculture as far as we can tell https://en.m.wikipedia.org/wiki/Neolithic_decline https://en.m.wikipedia.org/wiki/Neolithic_decline Climate change, the plague (usually one accompanied the other) and to a much lesser extent warfare occasionally reduced populations on a regional scale by more than 70%. Often leaving large areas very sparsely inhabited or even abandoned. As dar as we know the last major plague in Middle Earth occurred almost 1400 years before the events described in the LOTR yet the populations never seemingly recovered in much of it. In contrast in Europe recovery took about 300-400 years. However we must take into account that the plague remained endemic and kept reoccurring regularly during those periods, which put a massive downwards pressure on population growth. From what we can tell human populations can grow at an extremely fast pace by premodern standards if resources are ample and climatic conditions are good. For instance according to some estimates the populations of medieval England and some other countries in Northern Europe might have almost tripled between the 1100s and the 1300s. In a completely empty place like Eriador that must have happened at an even faster rate (e.g. the British colonies in New England). After the collapse of the Northern kingdoms Bree supposedly thrived for centuries without any major calamities. That doesn’t make any sense though, assuming a couple of thousand people lived there initially with all the ample land a population of ~2000 would have increased to over 100k at a somewhat conservative growth rate of ~2% (and it’s unlikely that its initial population could’ve ever been that low considering all the refugees etc.). Something similar applies to the Shire as well. So overall I don’t think we can really apply real world demographics to middle earth. There certainly must have been some force/factor not directly described by Tolkien that kept growth rates very low.