​Farmers use intensive pesticides to harvest cotton, which is harmful to not only the health of the farmers using them, but also our environment as it pollutes rivers and groundwater that negatively interfere with the ecosystem. Even though these farmers know of the health and environmental risks, they still use harmful pesticides to produce cotton, but why is this so. This stock and flow map should explain what impacts farmers to use pesticides to grow cotton despite the risks and explain the cause and effect relationship their use has on the cotton industry and the environment.

This is to support a discussion on money flows and growth. Money as a lubricant for the flow of embodied energy in human systems.
See also A Prosperous Way Down website

This model analyzes the interaction between climate change mitigation and adaptation in the land use sector using the concept of forest transition as a framework.

Graph representation of Ch3 of their 2007 Monetary Economics book, based on Alvarez and Ehnts 2015 paper The roads not taken. Also see more complex WIP to successively split sectors at IM-185550 . See also essence of MMT IM for simpler intro

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.

WIP replication of Khalid Saeed's draft paper presented by the Economics chapter of the SD Society in Sept 2019 youtube video

Book summary of Albert O Hirschman's 1982 book, explaining cycles of collective public action.

To maintain economic wealth (roads, hospitals, power lines, etc.) power needs to be consumed. The same applies to economic activity, since any activity requires the consumption of energy. According to the Environmental Protection Agency, the burning of fossil fuels was responsible for 79 percent of U.S. greenhouse gas emissions in 2010. So whilst economic activity takes place fossil fuels will be burned and CO2 emissions are unavoidable - unless we use exclusively renewable energy resources, which is not likely to occur very soon. However, the increasing CO2 concentrations in the atmosphere will have negative consequences, such droughts, floods, crop failures, etc. These effects represent limits to economic growth. The CLD illustrates some of the more prominent negative feedback loops that act as a break on economic growth and wealth.  As the negative feedback loops (B1-B4) get stronger, an interesting question is, 'will a sharp reduction in economic wealth and unavoidable recession lead to wide-spread food riots and disturbances?'

Eastern oyster growth model calibrated for Long Island Sound
Developed and implemented by Joao G. Ferreira and Camille Saurel; growth data from Eva Galimany, Gary Wickfors, and Julie Rose; driver data from Julie Rose and Suzanne Bricker; Culture practice from the REServ team and Tessa Getchis. This model is a workbench for combining ecological and economic components for REServ. Economic component added by Trina Wellman.

This is a one box model for an idealized farm with one million oysters seeded (one hectare @ a stocking density of 100 oysters per square meter)

1. Run WinShell individual growth model for one year with Long Island Sound growth drivers;

2. Determine the scope for growth (in dry tissue weight per day) for oysters centered on the five weight classes)
 
3. Apply a classic population dynamics equation:

dn(s,t)/dt = -d[n(s,t)g(s,t)]/ds - u(s)n(s,t)

s: Weight (g)
t: Time
n: Number of individuals of weight s
g: Scope for growth (g day-1)
u: Mortality rate (day-1)

4. Set mortality at 30% per year, slider allows scenarios from 30% to 80% per year

5. Determine harvestable biomass, i.e. weight class 5, 40-50 g (roughly three inches length)

WIP of Rammelt's 2019 System Dynamics Review Article which has STELLA and Minsky software versions as supplements. Compare with the older IM-2011 version

When people talk about a government deficit, they forget that this is only one side of the ledger. On the other is a corresponding non-government SURPLUS. The money the government spends is not lost but shows up in the private sector as income. When one talks only of the deficit then one can understand that many think it should be reduced or even converted into a surplus, but reducing the government deficit reduces private sector income and a government surplus forces a deficit on the private sector with a potentially devastating effect on private sector wealth and economic activity.  Unless the economy is overheating, government deficits are usually healthy. For countries that run traditionally a trade deficit, such as the US they are necessary to maintain economic activity. Consider this fact: for almost all of past 40 years the US and the UK have run deficits without any harmful effects!

Stephen P Dunn 2010 Book summary including Technostructure MMT PCT critical realist and managing perceptions links

An initial study of the economics of single use coffee pods.

ABOUT THE MODEL

This is a dynamic model that shows the correlation between the health-related policies implemented by the Government in response to COVID-19 outbreak in Burnie, Tasmania, and the policies’ impact on the Economic activity of the area.

 ASSUMPTIONS

The increase in the number of COVID-19 cases is directly proportional to the increase in the Government policies in the infected region. The Government policies negatively impact the economy of Burnie, Tasmania.

INTERESTING INSIGHTS

1. When the borders are closed by the government, the economy is severely affected by the decrease of revenue generated by the Civil aviation/Migration rate. As the number of COVID-19 cases increase, the number of people allowed to enter Australian borders will also decrease by the government. 

2. The Economic activity sharply increases and stays in uniformity. 

3. The death rate drastically decreased as we increased test rate by 90%.

No economy can function well without adequate funding and in the absence of finance will eventually fall into recession. Funds (financial assets in the model) are primarily injected through investments. This is certainly true for investments and payments undertaken by the government but also for private investments via bank loans. Net exports (i.e.trade surpluses) also represent an injecton of financial assets into the economy. By contrast financial assets are taken out of the economy through taxation, the repayment of bank loans and the running of a negative trade balance. Also, if the population in aggregate decides to save more this has the effect as if money were taken out of the economy. I have deliberately avoided specifying where the funds for treasury payments and public investments come from, as this is controversial. Modern Monetary Theory, for instance, says that these funds are not provided through tax revenue. Austerity can be seen as a process that deliberately diminishes or takes out financial assets from the economy through taxation, restrictions on bank loans or cutbacks in payments and public spending by the government. It is probably useful to look at insights 2740 and 2741 before examining this CLD because they provide the context and purpose for net public spending and investment.

An initial study of the economics of single use coffee pods.