First, it links all the relevant estimates, sources, and calculations for each of the case studies in Death by Government and all additional cases of lesser democide for which data have been collected. The value of this is the listing of each source, its estimate, and comments qualifying the estimate. From these others can check and evaluate Rummel's totals, refine and correct them, and build on this comprehensive set of data. These data are presented and annotated for pre-twentieth-century democide for the megamurderers and for the United States and lesser murderers. All data sources referenced in the democide tables are listed in the references. The methodological underpinnings for this collection have been given in Rummel's previous work, Death by Government, published by Transaction.Having finished collecting all these data and completing the major case studies Rummel systematically tests the assumed inverse relationship between democracy and democide. That is the substance of this book. Rummel details the tests and summarizes them. He concludes that the diverse tests are positive and robust, that the less liberal democracy and the more totalitarian a regime, the more likely it will commit democide. The closer to absolute power, the more a regime's disposition to murder one's subjects or foreigners multiplies.