The Phillips Machine (MONIAC)
The Phillips Machine, or Monetary National Income Analogue Computer (MONIAC), is a hydraulic representation of cash flow within the UK economy in the early 20th century. It represents the circular flow of income (New Zealand Institute of Economic Research, 2015), shown by the economic equation Aggregate Demand = Consumer Expenditure + Investment + Government Spending + (Exports – Imports), or Y = C + I + G + (X – M), which is an important equation in determining the national output of an economy (Pettinger, 2008). Though no longer in use, of the 14 that were built, the majority were originally restricted to military and government use owing to their effectiveness in determining economic policy. This paper describes an implementation of an emulation of this machine that satisfies, or mostly satisfies, almost all of the requirements specified in the ISO/IEC 25010 software quality assurance standard and would be suitable for deployment to support A-Level Economics teaching. With further work it would also become suitable as part of a museum display of a Phillips Machine.