Like previous models, this model shows the operation of a simple economy, the influence of changes in the consumption rate, and the effect of government intervention. In addition, this model shows changes in the hypothetical general price level. It gives an idea of changes in price trends based on changes in the quantity of money. NOTE: No general price level exists. Prices provide information for the exchange of individual economic goods.

WIP Summary of MIchael Hudson's Book Killing the Host: How Financial Parasites and Debt destroy the Global Economy 

Calculating EOQ using classical inventory model

This model is an attempt to simulate what is commonly referred to as the “pesticide treadmill” in agriculture and how it played out in the cotton industry in Central America after the Second World War until around the 1990s.

The cotton industry expanded dramatically in Central America after WW2, increasing from 20,000 hectares to 463,000 in the late 1970s. This expansion was accompanied by a huge increase in industrial pesticide application which would eventually become the downfall of the industry.

The primary pest for cotton production, bol weevil, became increasingly resistant to chemical pesticides as they were applied each year. The application of pesticides also caused new pests to appear, such as leafworms, cotton aphids and whitefly, which in turn further fuelled increased application of pesticides.

The treadmill resulted in massive increases in pesticide applications: in the early years they were only applied a few times per season, but this application rose to up to 40 applications per season by the 1970s; accounting for over 50% of the costs of production in some regions.

The skyrocketing costs associated with increasing pesticide use were one of the key factors that led to the dramatic decline of the cotton industry in Central America: decreasing from its peak in the 1970s to less than 100,000 hectares in the 1990s. “In its wake, economic ruin and environmental devastation were left” as once thriving towns became ghost towns, and once fertile soils were wasted, eroded and abandoned (Lappe, 1998).

Sources: Douglas L. Murray (1994), Cultivating Crisis: The Human Cost of Pesticides in Latin America, pp35-41; Francis Moore Lappe et al (1998), World Hunger: 12 Myths, 2nd Edition, pp54-55.

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

Simpler view IM-70351 combined with Economic ViewIM-69774 in preparation for integrating with Prevention Investment Framework (private) IM

Wealth can be seen as the factories, infrastructure, goods and services the population of a nation dispose of. According to Tim Garrett,  a scientist who looks at the economy from the perspective of physics, it is existing wealth that generates economic activity and growth. This growth demands the use of energy as no activity can take place without its use. He also points out that the use of this energy unavoidably  leads to concentrations of CO2 in the atmosphere.  All this, Tim Garrett says,  follows from the second law of thermodynamics.  If wealth decreases then so does economic activity and growth. The CLD tries to illustrate how wealth, ironically, now generates the conditions and feedback loops  that  may cause it to decline. The consequences are  inevitably economic  stagnation (or secular recession?). 

You can read about the connection Tim Garrett makes between 'Wealth, Economic Growth, Energy and CO2  Emissions' simply by Googling 'Tim Garrett and Economy'.

Simple model of the global economy, the global carbon cycle, and planetary energy balance.

Economic capital growth model, Figure 27 from Thinking in Systems by Donella H. Meadows

ECONOMIC GROWTH feeds on itself, provided the growth engine is fed with materials and finance. In this highly simplified representation  some of the factors that influence economic growth are show in the incircled green fields. Governments can influence economic growth positively via investments  and payouts. The most obvious tool which governments can use to slow an overheated economy is taxation.

Buying and storing electricity when it is cheap, and selling it when it is expensive. What are the benefits, both public and private?

This model simulates the economics of buying a home. It was created to compare buying a home against using investment returns to pay for rent. According to Micheal Finke, house prices typically run 20x monthly rental rates. 

Simple tragedy ​of the commons behavior model.

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

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.)

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

Primitive Legend:

Grocery Store Inventory is a stock that represents the amount of perishable food units available for sale to consumers. This stock is directly affected by the forces of economics as grocers can only sell at the level that their produce is demanded. As a result, once this stock exceeds demand, it will rise as food no longer sold.

Overstock Waste is a stock that is designed to model the overstock display assumption which states that consumers have more incentive to purchase foods from fully stocked piles rather than empty ones. This stock exists and accumulates over time because grocers purchase excess produce to give buyers incentive.

Ugly Food Stock is the stock that represent the amount of perfectly nutritious ugly produce neglected by consumers as they only buy the prettiest clusters from the display. This stock includes foods such as brown bananas, dented apples, and so forth. These ugly foods are left behind in addition to the overstock waste.

Education Programs is the stock that contains the amount of ugly foods delivered to local school districts for educating students on the significance of ugly food discrimination. These foods are utilized in various forms of comparative demonstrations to illustrate to students that ugly foods are just as nutritious as prettier alternatives.

Compost Alternatives is the stock that depicts the efforts of grocery stores trying to implement a method that allows them to reduce the amount of waste they send to the landfill. These compost methods may be in the form on enriched manure given back to the farmers that supply the produce.

10 Food Units/Resale Output is the variable that illustrates the amount of food units required to make a product for resale. For example, it takes 10 units of melons to make an assorted melon platter. Likewise, a single smoothie for resale will require 5 units of assorted fruits.

Develop a system model using the gathered  Biophysical, Socio-economic, and Cultural data of Iwahig

Challenge p.212 Business Dynamics, Sterman

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