This study analyzes economic and governmental factors in political violence, using both a cross-national quantitative analysis and an historical case study of El Salvador. Since at least the time of Aristotle, political violence has been a concern of social philosophers and social scientists. While it has often been seen primarily as revolutionary, political violence can be reconceptualized to include violent acts for political purposes carried out by an established regime as well as by its opponents. Such a broadening of the concepts facilitates neutral measurements of political violence, such as by death rate per population from domestic political conflict. For convenience, useful theories of political violence may be broken down into two main types. The first type, which may be called inequality theory, postulates some type of inequality, generally economic inequality, as a major cause of political violence. The second type of theory, which may be referred to as collective action theory, generally emphasizes the influence of the political interaction of competing actors. Other theories stress factors such as land inequality and population density. The cross-national analysis of this study found that income inequality and government sanctions were two of the more robust independent variables contributing to political violence. Similarly, the historical case study of El Salvador, particularly a comparison of the outbreaks of political violence occurring in 1932 and in 1979-84, suggests an important role in political violence was played by both income inequality and government sanctions. The findings that both of these variables contribute significantly and simultaneously to political violence implies that inequality theory and collective action theory may be partly compatible with each other. Also, the relationship between income inequality and political violence was found to be much stronger than the relationship between land inequality and political violence. This finding suggests that attempts to prevent political violence solely by addressing land inequality, as in many government land reform programs, will likely fall as long as they do not address the more fundamental factor of income inequality.