Mass killings under Communist regimes

Mass killings occurred under some Communist regimes during the twentieth century. Estimates of the death toll vary widely, depending on the methodology used. Scholarship focuses on the causes of mass killings in single societies, though some claims of common causes for mass killings have been made. Some higher estimates of mass killings include not only mass murders or executions that took place during the elimination of political opponents, civil wars, terror campaigns, and land reforms, but also lives lost due to war, famine, disease, and exhaustion in labor camps. There are scholars who believe that government policies and mistakes in management contributed to these calamities, and, based on that conclusion combine all these deaths under the categories "mass killings", democide, politicide, "classicide", or loosely defined genocide. According to these scholars, the total death toll of the mass killings defined in this way amounts to many tens of millions; however, the validity of this approach is questioned by other scholars. In his summary of the estimates in the Black Book of Communism, Martin Malia suggested a death toll of between 85 and 100 million people.