Explanation of the Model

This simple model describes wealth accumulation. The value in income is described by the following simple equation:

First pass at model depicting importance of Net Capital Accumulation on economic growth of firm - from firm's perspective

During the 'big recession' many governments have deliberately repressed salaries, usually via structural reforms, in order to gain competitivity. However, repression of salaries increases inequality, social discontent and often has counterintuitive effects. Salaries are a cost for companies, but they are also the basis for the demand for the goods and services they offer: people with little income cannot afford them. Scientific studies have shown repeatedly that economic growth generated via salary increases does not endanger the creation of employment, but rather reinforces it. In most countries, the 'positive effect of salary increases' eclipses any possible negative effects on export competitivity and even any detrimental effect on investment. A good example of such a study is the work of ONARAN and OBST on Wage-led Growth in the EU15 Member States (2016).  This positive dynamic has been highlighted in the model by prominent arrows. The policy implications for governments are clear! 

• This model examines how sustainable consumerism is from social, economic, and environmental aspects. The question in focus is "How will our second-hand clothing donations affect communities in developing countries, specifically Kenya?"

On the occasion of th G20-meeting in Toronto, the German Economics minister Herr Schaüble said that without restoring confidence it would not be possible to get consumer spending and business investment going. Similar remarks were made by David Cameron and Señor Zapatero of Spain. All maintain that confidence is a pre-requisite to get growth going and that, therefore, it was imperative to reduce fiscal deficits. Reducing the fiscal deficit will restore confidence at first. However, reducing the deficit very quickly will introduce a dynamic that may cause the economy to decline - and perhaps depress  consumers demand even further.  It will actually destroy confidence: few businesses are inclined to invest in a shrinking economy. Cutting the deficit too rapidly or too steeply can lead to a confidence trap.

NOTE: A big experiment is now taking place in the UK - the government has cut public spending severely! Will this lead to hardship and, perhaps, social unrest? 

Nobody seems to notice bubbles until they burst. One possible reason is that those caught up in a bubble are completely blinded by the grip, the overpowering logic and force excerted by the positive feedback loop that drives it. Financial bubbles occur time and time again - and nobody seems to learn. Another example on a different time scale is an argument that spins out of control and ends in violence. The participants seem to be blind to the consequences; the immediate and imperative logic of the feedback loop imposes itself. The vortex created by the feedback loop even seems to draw in outsiders, such as new investors. Is this the reason why we don't notice bubbles? This explanation is meant to stimulate discussion!

From Jay Forrester 1988 killian lectures youtube video describing system dynamics at MIT. For Concepts See IM-185226. For more detailed biography See Jay Forrester memorial webpage For MIT HIstory see IM-184930

Ocean/atmosphere/biosphere model tuned for interactive economics-based simulations from Y2k on.

Ocean/atmosphere/biosphere model tuned for interactive economics-based simulations from Y2k on.

The concept of 'CLOSING A FEEDBACK LOOP'  means that a loop is closed to affect the person or agents that originally are  responsible for an action so that they plainly feel its effects. This almost inevitable leads to corrective action. One of the reasons why climate change does not  arouse passion and action is that it is largely invisible and most people are not aware of it, although extreme weather events are beginning to change this somewhat. The schematic representation shows how systems thinking might help to draw attention to such situations by graphically connecting the dots to promote understand and hopefully action when people realize that there is a price to be paid for inaction.  Please note, however, that the loop does not describe dynamic behaviour in the normal system dynamics sense. 

This model shows the operation of a simple economy. It demonstrates the effect of changes in the fractional rate of consumption (or the converse, the fractional rate of saving.) It also, unlike Models 2 & 3, shows the influence Savings has on the production rate.

In summary, lower rates of consumption (based on production) result in higher rates of both production and consumption in the long-run.

Smithian growth model from Michael Joffe Fig. 3.7 p57 Ch3 Feedback Economics Book

A sample model for class discussion modeling COVID-19 outbreaks and responses from government with the effect on the local economy.  Govt policy is dependent on reported COVID-19 cases, which in turn depend on testing rates less those who recover

Based on chapter 14 of Modeling Dynamic Economic Systems

Ocean/atmosphere/biosphere model tuned for interactive economics-based simulations from Y2k on.

Implementation of a DSGE Model solved in a Macroeconomics class by Harald Uhlig (link), using Rational Expectations, in this case, the Hansens Real Business Cycle Model.

This Model was developed from the SEIR Model (Susceptible, Exposed, Infected, Recovered) and it predicts the COVID-19 outbreak in Burnie, Tasmania. This pandemic outbreak contributes to diverse rates including infection rate, death rates and recovery rate, government policies and its economic impacts.    

Assumptions:

 This model is driven by its determined rates, e.g., incubation rate, morality rate, test rate and immunity loss rate and its recovery rate.

Government policies are involved in fully vaccination rate, social distance, national border closure, travel, and business restriction which effect Burnie’s economy.

There are three economic entities dimensions in Burnie Island, we can tell that the pandemic has negative impact on Brick-and-Mortar enterprises and tourism business to some extent, whereas, e commercial business plays a crucial role to stimulate the regional economic activities during the COVID-19 period.

 

Interesting Insights:

 The figure of susceptible changes significantly during the initial 3 weeks because of low recovery rate and high infection rate. On the other hand, the implementation and interventions of government policies is effective, because the number of patients who tested negative is increased and the majority of them release and go back home after medical follow-up.