
The problem as I see it is that though a meticulous scholar, Max Weber is the father of erudite sophistry which passes as punditry. Though he was arguably a fox, his genealogy has given rise to many hedgehogs.
Weber is famous for his work on relating the Protestant ethic and capitalism (more precisely, Calvinism). In general I think Weber is less right than he is wrong on this issue. But the bigger problem is that Weber’s style of interpretative historical analysis also has spawned many inferior and positively muddled imitators, whether consciously or not.
To my mind the problems with Weber’s sweeping generalizations, interpretations, and inferences, are clearest on the topic of China. His assertions on the nature of the Chinese mind informed by Confucianism, and how it would relate to (and hinder) modern economic development are very hit or miss.

And some of that may be attributable to Confucianism in a distant causal sense, because the cultural sensibility does encourage the development of broad-based literacy through self-cultivation. In Strange Parallels Victor Lieberman notes the contrast between Vietnam, with its more Sinic cultural orientation, and the rest of Southeast Asia, with their Indic Theravada Buddhist cultures.
The Vietnamese elites’ orientation toward Confucianism meant that there was stratification in society, as there were constant upward and downward movements across class. The chasm between the Confucian literati and the peasantry was large. In contrast in Cambodia popular religion was relatively unifying due to its accessibility. But it is notable to me that Vietnam in particular is often perceived by those who travel in Southeast Asia to be an industrious and striving nation.
So yes, culture may matter. But simple economic forces, and material conditions, are incredibly important, and our understanding of their origins are more mysterious than we’d like to think.

But the genetic data seem clear that African slavery increased greatly during the Islamic period, resulting in a much more human agony, as so many of the slaves died en route (males who were to be eunuchs had a high mortality rate as they had to be castrated before entering Muslim lands). This had nothing to do with the cruelty of Islam per se, but the overall development and advancement of the Eurasian oikoumene, and the role of African slave labor in its post 1000 A.D. economy.
In fact one might argue that the unity of the Islamic world, and its relatively uniform legal and cultural superstructure after the collapse of its political unity, was a factor in fostering the rise of the global slave trade. That is, Islam generated asabiya, social solidarity, within the group, but this ultimately was to the detriment of those who were outside of the group.

That dynamic was driven by economics (in the American case, the triangle trade).
Similarly, the mortality rates of slaves varied greatly by locale and the what they cultivated. The sugar islands were death traps. The rice farmers of coastal South Carolina lived relatively stable lives, even comparable to serfs. Those who grew tobacco were somewhere in the middle. All were under English jurisdiction. The mortality of Brazilian slaves was high, but nominally Roman Catholic jurisdictions were subject to more humanitarian codes. But the primary determinants of mortality, of humanity, were economic. Material, even if ideological variables had an impact on the margin (Rodney Stark has argued that the French legal system was more humanitarian in Louisiana, and one can see this in various vital statistics).
Obviously ideological and material forces interact and influence each other. My point here is to observe that too often public commentary gets caught up on the idea of the great idea driving history. But once we have some distance it is often obvious that on the proximate scale many of the patterns we see are constrained, driven, and conditioned, on material forces and parameters.

And here we are!
* I said “institutional chattel slavery” specifically to head off annoying nit-picking comments. Please don’t.
