Taylor has presented a fascinating analysis of ancient Roman revenue vs. military costs from 280 - 168 BCE. While it is always prudent to treat any attempt to determine specific financial facts about an ancient society, Taylor uses every resource available. Therefore, his assessment of Roman finances carry significant weight.
He shows quite clearly that Rome's Republican organization and its various methods of incorporating conquered peoples into the Republic elevated it above other major powers of the time. Rather than heavily taxing conquered peoples (as other powers did), Rome lightly taxed them (if at all) and instead required them to provide troops when needed and pay their salaries. As a result, Rome could field tens of thousands of men at a minimal cost. The other powers of the day could not do so; thus, Rome was able to conquer numerous peoples, keep them happy (mostly) with the Republic, and have a resilience that lasted a thousand years in the west. Or, as Michael Mann would say, Rome had "infrastructural power."
Taylor stated in his conclusions: "The Middle Republican State was a sophisticated and subtle engine of resource extraction and deployment with, by contemporary standards, extraordinarily high infrastructural capacity. If it had not been, the course of Mediterranean geopolitical history could have been very different."
Please note that this book is extremely detailed and may not appeal to the casual historian. However, those who are seriously interested in, and familiar with, ancient Roman history will find the information in the book absolutely engrossing.