In this book the authors analyze several correlations that lead to rise and fall of the States based on population growth, labor market demands and excesses of upper classes.
I did not find their approach particularly innovative. One thing I remembered from this book is "plateau" stage they called stagflation. This is a stage in state's secular development when population saturation leads to wage decline that coincides with maximum profits for upper classes.
I would say that USA has entered stagflation phase in the beginning of 21st century. Based on the authors evaluations of several historical Empire States that went through secular cycles, it appears that stagflation phase could persist for decades, even for centuries. Though it inevitably leads to a crisis and fall, followed by renewed cycle.
posted by David