Entrenchment: Wealth, Power, and the Constitution of Democratic Societies, by Paul Starr, revisits the history of political economy through the lens of a novel concept: that of entrenchment. Policies that benefit some interest groups may become entrenched and persist in spite of subsequent evolutions. Such entrenchment in turn explains why crises occur, sometimes degenerating into violent conflicts: there is a tension between entrenched custom and the need for societal change, or more simply the fact that the balance of power has shifted. (JEL D02, D31, D72, N40)