He also deals with the concept of crisis and business cycle, two economic theories that Marx pioneered (p. 39). The last section, Marx the Teacher, evaluates the usefulness of Marx's thought to interpret the events of his time and those between his death and Schumpeter's time. Schumpeter claims that any theory of crisis gains support when crises occur, and points to some areas where Marx's theories have failed to predict. On page 53 he argues that the theory better predicts English and Dutch colonial experiences in the Tropics but fails when applied to New England for example.