Fun thing to study and read about. The differences are quite small though. Wouldn't the error bars dwarf the differences? I'd assume you could tweak various assumptions and easily arrive at another conclusion.<p>I know that the Romans were good at record keeping for their time. But I understand the best population estimates for the Roman empire are based on economic metrics like agricultural modeling which in turn must make assumptions about wealth distribution. As for the Han, I don't think they've left us a complete census either.<p>To quote "How Many People? Ancient Demography" [0]:<p>> We generally estimate uncounted women, children and elderly males by using demographic modeling based on model life tables – data tables which project mortality simulations based on real-world populations. But how do you know what tables to use? The answer here has typically been that you comb the evidence you have (grave inscriptions, fragmentary census records that survive in Egypt) to create a statistical snapshot of your population and then try to match that, as best you can, to one of the extant models that ‘best fits.’ [...]<p>> That leaves the question of how many enslaved persons and those too poor to be counted in some of our figures.<p>[0] <a href="https://acoup.blog/2023/12/22/collections-how-many-people-ancient-demography/" rel="nofollow">https://acoup.blog/2023/12/22/collections-how-many-people-an...</a>