MONIAC facts for kids
The MONIAC (which stands for Monetary National Income Analogue Computer) was a special kind of computer. It was also known as the Phillips Hydraulic Computer. A clever economist from New Zealand named Bill Phillips created it in 1949. He built it to show how the economy of the United Kingdom worked. Phillips was a student at the London School of Economics (LSE) when he made it.
The MONIAC is an analogue computer. This means it used physical things, like water, to represent numbers and processes. It used fluidic logic, which is like using liquids to do calculations, to show how an economy functions. The name MONIAC combines "money" with "ENIAC," which was an early electronic digital computer.
Contents
How the MONIAC Worked
The MONIAC was quite large, about 2 meters (6.5 feet) tall, 1.2 meters (4 feet) wide, and almost 1 meter (3 feet) deep. It had many clear plastic tanks and pipes attached to a wooden board. Each tank stood for a different part of the UK's national economy. The flow of money around the economy was shown by colored water moving through the system.
At the very top of the board was a big tank called the treasury. Water, representing money, flowed from this treasury tank to other tanks. These other tanks showed the different ways 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. This would let water drain from the treasury into the health spending tank. The water then flowed further down the model to other tanks, showing how different parts of the economy interact.
Water could also be pumped back to the treasury from some tanks. This represented taxation. If tax rates changed, the pumping speeds would increase or decrease to show this.
Savings and Investment
Savings reduce the money available to people for spending. On the other hand, investment income increases that money. The MONIAC showed this by draining water (representing savings) from the spending flow. It would also inject water (representing investment income) into that flow.
If the savings flow was more than the investment flow, the water level in a special tank (the surplus-balances tank) would rise. This showed that money was building up. If investment flow was more than savings for a while, this tank would run dry. Imports and exports were shown by water draining out of the model (imports) or by extra water being poured in (exports).
Automatic Control and Accuracy
The flow of water was controlled automatically. It used a system of floats, counterweights, electrodes, and cords. When the water in a tank reached a certain level, pumps and drains would turn on. Phillips and his helper, Walter Newlyn, were surprised to find that the MONIAC could be set up to be very accurate, within 2%.
The way water flowed between the tanks followed economic rules. Different economic settings, like tax rates or investment rates, could be changed. This was done by adjusting valves that controlled the water flow. Users could try different settings and see what happened. The MONIAC was a powerful tool for its time. It could show how many different things in the economy affected each other.
When the settings created a stable economy, the model would settle down. The results could then be read from scales. The computer's output could even be sent to a simple plotter to draw graphs.
Teaching and Simulation
The MONIAC was designed to help teach economics. But it also turned out to be a good way to simulate, or test, economic ideas. In 1949, electronic digital computers that could run complex economic simulations were not available. The few computers that existed were mostly for government or military use. They also didn't have good screens to show how complex models worked.
Watching the MONIAC in action made it much easier for students to understand how all the parts of a national economy fit together. Many different organizations bought a MONIAC, showing it was used for both teaching and testing ideas.
Phillips gathered materials to build his first MONIAC. He even used parts from old Lancaster bombers that were left over from the war. The first MONIAC was built in his landlady's garage in Croydon. It cost about £400, which would be worth much more today (equivalent to £10,000 in 2021).
Phillips first showed the MONIAC to important economists at the LSE in 1949. They liked it very much, and Phillips was soon offered a teaching job at the LSE.
Where You Can Find MONIACs
It is believed that between twelve and fourteen MONIAC machines were built in total. Here are some places where they can be found:
- The very first MONIAC was given to the Economics Department at the University of Leeds. It is now on display in the reception area of the university's Business School.
- Other copies went to three more British universities.
- Some MONIACs went to the Harvard Business School and Roosevelt College in the United States. One also went to Melbourne University in Australia.
- The Ford Motor Company and the Central Bank of Guatemala are thought to have bought MONIACs.
- A MONIAC owned by Istanbul University is in its Faculty of Economics and can be seen there.
- A MONIAC from the LSE was given to the Science Museum in London. After being carefully looked after, it is now on public display in the museum's mathematics galleries.
- Another MONIAC from the LSE was given to the New Zealand Institute of Economic Research in Wellington, New Zealand. This machine was part of New Zealand's display at the Venice Biennale in 2003. It was set up to model the New Zealand economy. In 2007, this machine was fixed up and put on permanent display in the Reserve Bank of New Zealand Museum.
- A working MONIAC, also known as a Phillips Machine, is at the Faculty of Economics at Cambridge University in the United Kingdom. Allan McRobie from the Cambridge University Engineering Department restored this machine. He gives a demonstration to students every year.
- A copy of the MONIAC from the central bank of Guatemala was made for an exhibition in 2005-2006. This exhibition was called "Tropical Economies" and was at the Wattis Institute of the California College of the Arts in San Francisco.
- The MONIAC at The University of Melbourne, Australia, is always on display. You can find it in the lobby of the Giblin Eunson Library (Ground Floor, Business and Economics Building, 111 Barry Street, Carlton, Melbourne). The university has looked for people interested in restoring this MONIAC.
- Erasmus University Rotterdam (EUR) has owned a MONIAC since 1953. It was a gift from the City of Rotterdam for the university's 40th anniversary. It is located in the THEIL building.
- Clausthal University of Technology in Germany has one in its faculty of economic sciences.
- Vrije Universiteit Amsterdam had a MONIAC built in 1951 by their instrument makers, based on the original design. It was called the ECOCIRC (Economic Flow Circulator Demonstrator). It is located on the 8th floor of the Main Building.
MONIAC in Popular Culture
The Terry Pratchett novel Making Money features a similar device as a main part of the story. In the book, after the machine is made perfect, it magically becomes directly connected to the economy it was supposed to simulate. This means the machine cannot be changed without actually changing the real economy. This is a funny take on Goodhart's law.
See also
- Analog computer
- Hydraulic macroeconomics
- Phillips curve
- Water integrator
Documentary
- "The League of Gentlemen". Third Episode of Pandora's Box, a documentary produced by Adam Curtis.
