I reviewed Power and Plenty in TNR here. Findlay and O’Rourke use social-science modeling and the counterfactual method to good purpose:

Even if elements of this story seem familiar, Findlay and O’Rourke tell their tale exceptionally well and give lively attention to alternate possibilities: What should have happened, according to theory? What could have happened, in the realm of plausibility? They find they can cede little to neoliberal economists: Power was generally necessary to secure plenty. “Adam Smith and his liberal followers to the present day, however, would, and have, argued that much of this [state] expenditure was wasted, unnecessarily crowding out more productive private investment. The assumption of course is that the markets and raw material supplies … would have existed regardless”–which, history suggests, they would not have. Had your empire not secured them, your neighbor’s would have, with lasting bad consequences to you.

The sentiment I most liked that didn’t make it into the final draft: it’s a thing of joy if you’re a fact-nerd like me.