Two narratives of economic development are presented. The first highlights contemporary global wealth and income inequality. The second illustrates historical aggregate gains in global wealth and income. Within these two broad narratives of economic development, protests and social movements will arise to modulate feelings of unfairness and deprivation. A new theory of social movements is developed. Collective remembering and collective imagining can inform feelings of unfairness, frustration, and relative deprivation in the present. This theory highlights the importance of a temporal account of the development of social movements within democracies that allow for the expression of civic discontent without brutalization. The theory predicts aggregate global economic development, with unequal economic gains, will always necessitate social movements to modulate economic inequality and circumvent perceived and actual hardship. The implications of this theory for understanding globalization, social movements, and creating fairer democratic societies are discussed.