The MONIAC (Monetary National Income Automatic Computer) also known as the Phillips Hydraulic Computer and the Financephalograph, was created in 1949 by the New Zealander economist Bill Phillips to model the national economic processes of the United Kingdom, while Phillips was a student at the London School of Economics (LSE), The MONIAC was an analogue computer which used hydraulics to model the workings of an economy. The MONIAC name may have been suggested by an association of money and ENIAC, an early electronic digital computer.
The MONIAC was approximately 2 m high, 1.2 m wide and almost 1 m deep, and consisted of a series of transparent plastic tanks and pipes which were fastened to a wooden board. Each tank represented some aspect of the UK national economy and the flow of money around the economy was illustrated by coloured water. At the top of the board was a large tank called the treasury. Water (representing money) flowed from the treasury to other tanks representing the various ways in which a country could spend its money. For example, there were tanks for health and education. To increase spending on health care a tap could be opened to drain water from the treasury to the tank which represented health spending. Water then ran further down the model to other tanks, representing other interactions in the economy. Water could be pumped back to the treasury from some of the tanks to represent taxation. Changes in tax rates were modeled by increasing or decreasing pumping speeds.
