A critique of the ergodic/nonergodic approach to uncertainty

Although uncertainty is widely viewed as an essential element of post Keynesianism, two contrasting perspectives on its nature and foundations compete for attention–the ontologically oriented ergodic/nonergodic (ENE) approach, and the epistemologically oriented human abilities and characteristics (HAC) approach. Since little or no direct debate has previously occurred between the two perspectives, this paper presents an extended critique of the ENE approach in both general and Keynes-specific terms. The critique argues, inter alia, that the ENE approach is untenable because it makes it impossible for agents to obtain knowledge of the relevant state of reality; it employs two conflicting definitions of ergodicity; its accounts of agent learning are incoherent or internally inconsistent; it commits the excluded middle fallacy; its view of causality is oversimplified; and its treatment of Keynes’s philosophical work is inaccurate and tendentious. General aspects of the critique also apply to other schools employing the ENE approach.