This model simulates a COVID outbreak occurring at Burnie, Tasmania.
It links the extent to the pandemic with governments intervention policies
aiming to limit the spread of the virus. The other part of the model illustrates
how will the COVID statistics and the government enforcement jointly influ

This model simulates a COVID outbreak occurring at Burnie, Tasmania. It links the extent to the pandemic with governments intervention policies aiming to limit the spread of the virus. The other part of the model illustrates how will the COVID statistics and the government enforcement jointly influence the economic environment in the community. A number of variables are taken into account, indicating positive or negative relationship in the infection and the economy model respectively.

 

Assumptions

·         Government takes responsive actions when the number of acquired cases exceeds 10.

·         Government’s prompt actions, involving closure of the state border, lockdown within the city, plans on mandatory vaccination and testing, effectively control the infection status.

·         Economic activities are reduced due to stagnation in statewide tourism, closure of brick-and-mortar businesses, and increased unemployment rate, as results of government restrictions.

 

Insights

Government’s rapid intervention can effectively reduce the infected cases. The national vaccination rollout campaign raises vaccination rate in Australians, and particularly influence the death rate in the infection model. Please drag the slider of vaccination to a higher rate and run the model to compare the outcomes.

Although local economy is negatively affected by government restriction policies, consumer demand in online shopping and government support payments neutralize the negative impact on economy and maintain the level of economic activities when infections get controlled. 

Fig.5 Generic resource allocation structure from Khalil Saeed and Oleg Pavlov's Dynastic Cycles SD model  paper   See also  the SD  Model Insight
Fig.5 Generic resource allocation structure from Khalil Saeed and Oleg Pavlov's Dynastic Cycles SD model paper  See also  the SD Model Insight
 
			 
				 
					 From Oatley 2014 p214++   Balance-of-Payments Adjustment
  
					 Even though the current and capital accounts must balance each other, there
is no assurancethat the millions of international transactions that individu-
als, businesses, and governments conduct every year will nece

From Oatley 2014 p214++

Balance-of-Payments Adjustment

Even though the current and capital accounts must balance each other, there is no assurancethat the millions of international transactions that individu- als, businesses, and governments conduct every year will necessarily produce this balance. When they don’t, the country faces an imbalance of payments. A country might have a current-accountdeficit that it cannotfully finance throughcapital imports, for example, or it might have a current-accountsur- plus thatis not fully offset by capital outflows. When an imbalancearises, the country must bring its payments back into balance. The process by which a country doessois called balance-of-payments adjustment. Fixed and floating exchange-rate systems adjust imbalances indifferent ways.

In a fixed exchange-rate system, balance-of-payments adjustment occurs through changes in domestic prices. We can most readily understand this ad- justmentprocess through a simple example. Suppose there are only two coun- tries in the world—the United States and Japan—and supposefurther that they maintain a fixed exchange rate according to which $1 equals 100 yen. The United States has purchased 800 billion yen worth of goods, services, and financial assets from Japan, and Japanhas purchased $4 billion of items from the United States. Thus, the United States has a deficit, and Japan a surplus, of $4billion. 

This payments imbalance creates an imbalance between the supply of and the demandfor the dollar and yen in the foreign exchange market. American residents need 800 billion yen to pay for their imports from Japan. They can acquirethis 800 billion yen by selling $8 billion. Japanese residents need only $4 billion to pay for their imports from the United States. They can acquire the $4 billion by selling 400billion yen. Thus, Americanresidentsareselling $4 billion more than Japanese residents want to buy, and the dollar depreci- ates againstthe yen.

Because the exchangerateis fixed, the United States and Japan must prevent this depreciation. Thus, both governmentsintervenein the foreign exchange market, buying dollars in exchange for yen. Intervention has two consequences.First, it eliminates the imbalance in the foreign exchange mar- ket as the governments provide the 400billion yen that American residents need in exchange forthe $4 billion that Japanese residents do not want. With the supply of each currency equalto the demandin the foreign exchange mar- ket, the fixed exchangerate is sustained. Second, intervention changes each country’s money supply. The American moneysupply falls by $4 billion, and Japan’s moneysupplyincreases by 400billion yen. 

The change in the money supplies alters prices in both countries. The reduc- tion of the U.S. money supply causes Americanpricesto fall. The expansion of the money supply in Japan causes Japanese prices to rise. As American prices fall and Japanese prices rise, American goods becomerelatively less expensive than Japanese goods. Consequently, American and Japaneseresidents shift their purchases away from Japanese products and toward American goods. American imports (and hence Japanese exports) fall, and American exports (and hence Japanese imports) rise. As American imports (and Japanese exports) fall and American exports (and Japanese imports) rise, the payments imbalanceis elimi- nated. Adjustment underfixed exchange rates thus occurs through changesin the relative price of American and Japanese goods brought about by the changes in moneysupplies caused by intervention in the foreign exchange market.

In floating exchange-rate systems, balance-of-payments adjustment oc- curs through exchange-rate movements. Let’s go back to our U.S.—Japan sce- nario, keeping everything the same, exceptthis time allowing the currencies to float rather than requiring the governments to maintain a fixed exchangerate. Again,the $4 billion payments imbalance generates an imbalancein the for- eign exchange market: Americansare selling more dollars than Japanese resi- dents want to buy. Consequently, the dollar begins to depreciate against the yen. Because the currencies are floating, however, neither governmentinter- venesin the foreign exchange market. Instead, the dollar depreciates until the marketclears. In essence, as Americans seek the yen they need, they are forced to accept fewer yen for each dollar. Eventually, however, they will acquire all of the yen they need, but will have paid more than $4 billion for them.

The dollar’s depreciation lowers the price in yen of American goods and services in the Japanese market andraises the price in dollars of Japanese goodsandservices in the American market. A 10 percent devaluation of the dollar against the yen, for example, reduces the price that Japanese residents pay for American goods by 10 percentandraises the price that Americans pay for Japanese goods by 10 percent. By making American products cheaper and Japanese goods more expensive, depreciation causes American imports from Japan to fall and American exports to Japan to rise. As American exports expand and importsfall, the payments imbalanceis corrected.

In both systems, therefore, a balance-of-payments adjustment occurs as prices fall in the country with the deficit and rise in the country with the surplus. Consumers in both countries respond to these price changes by purchasing fewer of the now-more-expensive goods in the country with the surplus and more of the now-cheaper goodsin the country with the deficit. These shifts in consumption alter imports and exports in both countries, mov- ing each of their payments back into balance. The mechanism that causes these price changes is different in each system, however. In fixed exchange- rate systems, the exchange rate remains stable and price changes are achieved by changing the moneysupplyin orderto alter prices inside the country. In floating exchange-rate systems, internal prices remain stable, while the change in relative prices is brought about through exchange-rate movements.

Contrasting the balance of payments adjustment process under fixed and floating exchangerates highlights the trade off that governments face between

exchangerate stability and domestic price stability: Governments can have a stable fixed exchangerate or they can stabilize domestic prices, but they cannotachieve both goals simultaneously. If a government wants to maintain a fixed exchangerate, it must accept the occasional deflation and inflation caused by balance-of-payments adjustment. If a governmentis unwilling to accept such price movements,it cannot maintain a fixed exchangerate. This trade-off has been the central factor driving the international monetary system toward floating exchange rates during the last 100 years. We turn now to examine howthis trade-off first led governmentsto create innovativeinter- national monetary arrangements following World WarII and then caused the system to collapse into a floating exchange-rate system in the early 1970s. 

Collapse of the economy, not just recession, is now very likely. To give just one possible cause,
in the U.S. the fracking industry is in deep trouble. It is not only that most
fracking companies have never achieved a   free cash flow   (made a profit)
since the fracking boom started in 2008, but th
Collapse of the economy, not just recession, is now very likely. To give just one possible cause, in the U.S. the fracking industry is in deep trouble. It is not only that most fracking companies have never achieved a free cash flow (made a profit) since the fracking boom started in 2008, but that  an already very weak  and unprofitable oil industry cannot cope with extremely low oil prices. The result will be the imminent collapse of the industry. However, when the fracking industry collapses in the US, so will the American economy – and by extension, probably, the rest of the world economy. To grasp a second and far more serious threat it is vital to understand the phenomenon of ‘Global Dimming’. Industrial activity not only produces greenhouse gases, but emits also sulphur dioxide which converts to reflective sulphate aerosols in the atmosphere. Sulphate aerosols act like little mirrors that reflect sunlight back into space, cooling the atmosphere. But when economic activity stops, these aerosols (unlike carbon dioxide) drop out of the atmosphere, adding perhaps as much as 1° C to global average temperatures. This can happen in a very short period time, and when it does mankind will be bereft of any means to mitigate the furious onslaught of an out-of-control and merciless climate. The data and the unrelenting dynamic of the viral pandemic paint bleak picture.  As events unfold in the next few months,  we may discover that it is too late to act,  that our reign on this planet has, indeed,  come to an abrupt end?  
 ​HYSTERESIS  The lost energy associated with delay. Hysteresis is the dependence of a system not only on its current environment but also on its past environment. This dependence arises because the system can be in more than one internal state. To predict its future development, either its internal
​HYSTERESIS
The lost energy associated with delay.
Hysteresis is the dependence of a system not only on its current environment but also on its past environment. This dependence arises because the system can be in more than one internal state. To predict its future development, either its internal state or its history must be known.[1] If a given input alternately increases and decreases, the output tends to form a loop as in the figure. However, loops may also occur because of a dynamic lag between input and output.
Hysteresis is produced by positive feedback to avoid unwanted rapid switching. Hysteresis has been identified in many other fields, including economics and biology.

Economic systems can exhibit hysteresis. For example, export performance is subject to strong hysteresis effects: because of the fixed transportation costs it may take a big push to start a country's exports, but once the transition is made, not much may be required to keep them going.
Hysteresis is used extensively in the area of labor markets. According to theories based on hysteresis, economic downturns (recession) result in an individual becoming unemployed, losing his/her skills (commonly developed 'on the job'), demotivated/disillusioned, and employers may use time spent in unemployment as a screen. In times of an economic upturn or 'boom', the workers affected will not share in the prosperity, remaining long-term unemployed (over 52 weeks). Hysteresis has been put forward[by whom?] as a possible explanation for the poor unemployment performance of many economies in the 1990s. Labor market reform, or strong economic growth, may not therefore aid this pool of long-term unemployed, and thus specific targeted training programs are presented as a possible policy solution.

One type of hysteresis is a simple lag between input and output. A simple example would be a sinusoidal input X(t) and output Y(t)that are separated by a phase lag φ:

Such behavior can occur in linear systems, and a more general form of response is

where χi is the instantaneous response and Φd(t-τ) is the response at time t to an impulse at time τ. In the frequency domain, input and output are related by a complex generalized susceptibility.[3]

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 c
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.
 This
paper aims at describing a case where system dynamics modeling was used to evaluate
the effects of information and material supply lead-time variation on sales
contributions margins and operating cash conversion cycle of a commodity export
business.  An empirical dynamic model,
loaded with eco

This paper aims at describing a case where system dynamics modeling was used to evaluate the effects of information and material supply lead-time variation on sales contributions margins and operating cash conversion cycle of a commodity export business.  An empirical dynamic model, loaded with econometric theory of price effect on competitive demand, was used to describe the input data.  The model simulation outputs proved themselves relevant in analyzing the complex interconnections of multiple variables affecting  the profitability in a commercial routine, supporting the decision process among sales managers.

Archetype:  Success to the successful The more pioneer seed being sold, the more corn is grown.  As more corn is grown, the more pioneer seeds are needed for the next harvest.  More people began using the pioneer seeds, less people used the Ghanaian seeds.  However, the pioneer seed is expensive, so
Archetype:  Success to the successful
The more pioneer seed being sold, the more corn is grown.  As more corn is grown, the more pioneer seeds are needed for the next harvest.  More people began using the pioneer seeds, less people used the Ghanaian seeds.  However, the pioneer seed is expensive, so not everyone could buy the pioneer seed.  The more people using Ghanaian corn seeds, less people were using pioneer seeds.  

Way out: 
The best way out of this would probably be to lower the price of the pioneer seed.  The pioneer seed produces more corn that is sweeter.  People prefer this corn over the corn from the Ghanaian seeds.  More people are using the pioneer seeds, so gradually Ghanaian seeds will no longer be used.  Lowering the price of pioneer seeds will make it available to more farmers.  This way, less farmers will go out of business from trying to compete with more sweeter corn.  

Sources:
 Randall, R. (2014, December 15). Are African farmers in danger of becoming slaves to patented seeds? | Genetic Literacy Project. Retrieved January 18, 2016, from https://www.geneticliteracyproject.org/2014/12/15/are-african-farmers-in-danger-of-becoming-slaves-to-patented-seeds/

Is 4-H trying to hook African farmers on costly seeds? (2014, November 17). Retrieved January 18, 2016, from http://grist.org/food/is-4-h-trying-to-hook-african-farmers-on-costly-seeds/

Butler, K. (n.d.). How America's favorite baby-goat club is helping Big Ag take over farming in Africa. Retrieved January 18, 2016, from http://www.motherjones.com/environment/2014/11/4h-africa-farming-dupont-hybrid-seeds 
Overview of Part G Ch 27 to 30 of Mitchell Wray and Watts Textbook see  IM-164967  for book overview
Overview of Part G Ch 27 to 30 of Mitchell Wray and Watts Textbook see IM-164967 for book overview
 This model is to explain the COVID-19 outbreak in Brunie Island, Tasmania, Australia, and the relationship between it and the government policies , also with the local economy.      This model is upgraded on the basis of the SIR model and adds more variables.      A large number of COVID-19 cases w
This model is to explain the COVID-19 outbreak in Brunie Island, Tasmania, Australia, and the relationship between it and the government policies , also with the local economy.

This model is upgraded on the basis of the SIR model and adds more variables.

A large number of COVID-19 cases will have a negative impact on the local economy. But if the number of cases is too small, it will have no impact on the macro economy

Government policy will help control the growth of COVID-19 cases by getting people tested.