It's hard to find academic population estimates of Abbasid Iraq. McEvedy and Jones' Atlas of World Population history gives a peak of 2.5 million. However, given the common estimates of ~1 million people in Abbasid Baghdad at its height, that would give Iraq a ridiculously high urbanization rate of 40%.
I know the Dutch reached urbanization rates like that during their Golden Age, but they had very efficient agriculture, and even they had to import lots of grain from the Baltic to feed their cities.
Has more recent work been done on the population of Abbasid Baghdad and Iraq? What do modern scholars think about their historical populations? As an aside, are there any other regions in the pre-industrial era that reached such high urbanization rates?
Ira Lapidus' history quotes a figure of 300,000-500,000. This source, which goes further in claiming that its estimate is based on the total area of the city in hectares, likewise estimates the population at 500,000.
As an aside, are there any other regions in the pre-industrial era that reached such high urbanization rates?
Lapidus notes that it would have been the largest city in the world at the time outside of China. As to the "urbanization rate," I mean, compared to what? Just "Iraq"? At the time the Abbasid empire would have been much larger, so I'm not sure why the "rate" would be so high.