Well, doesn’t the Harappan civilization make a mess out of all this? Tin was nearby, and there’s evidence of bronze artifacts in all kinds of houses across the cities, and in general less evidence of hierarchical power, and certainly nothing like the concentration you see in other Bronze Age civilizations. We don’t have the civilization surviving as is to the Iron Age, because it depopulated before iron smelting became common. But it’s odd to make the claim bronze had to lead to stratified societies. Clearly, not always.

I agree. The author is stretching several assumptions to get to his conclusions. The sub-title suggests he has solved the "Bronze Age collapse" riddle but his statement can simply be considered one of many factors already pointed out in the literature -- not the main reason.

The claim (as I understand it) is that power was centralized because tin was rare--i.e., had to be imported via sophisticated trade routes, which presumably could be controlled by the state.

In an area where tin is abundant, individuals could easily forge their own bronze weapons, thus making it harder for the state to have a monopoly on high-tech weapons.

So I think the Harappan actually reinforce the theory.