Abstract for: A System Dynamics View of the Phillips Machine

Although system dynamics practitioners appeal to a bathtub analogy to explain the basic concepts of system dynamics, few physical water based models have been used for this purpose. The celebrated Phillips machine, a hydraulic macroeconomics model built in 1949, illustrates how this was done for a serious model of a macroeconomic system. This paper reviews the physical modeling constructs exemplified by the Phillips machine, relates them to standard system dynamics notation, and proposes two similar machines to represent basic structures in system dynamics instruction.