Historical Political Economy (HPE) is the study of how political and economic actors and institutions have interacted over time. It differs from much of economic history in that it focuses on the causes and consequences of politics. It departs from much of conventional political economy in that its context is strictly historical, even if/when it has implications for contemporary political economy. It also departs from much of history in its use of social-scientific theory and methods. Thus, while HPE involves elements of the traditional fields of economics, political economy, and history, it is separate from-and integrative of-them.