This Loan Cost Model is the second in the series. It takes into account the potential cost of student loans in the case that the student does not manage to graduate college or does not succeed in their career.
The model starts in 1900. In the year 2000 you get the chance to set a new emission target and nominal time to reach it. Your aim is to have atmospheric CO2 stabilize at about 400 ppmv in 2100. From Sterman, John D. (2008) Risk Communication on Climate: Mental Models and Mass Balance. Science 322 (24 October): 532-533.
Investigations into the relationships responsible for the success and failure of nations. This investigation was prompted after reading numerous references on the subject and perceiving that *Why Nations Fail: The Origins of Power, Prosperity, and Poverty* by Acemoglu and Robinson seem to make a great deal of sense.
The simple savings account is used to demonstrate the nature of a reinforcing loop. Change the initial amount and interest rate and run the model to see the implications of changing these values.
Based on 1990 SDR Article. Control systems act to make their own input match internal standards or reference signals. Competent control systems create illusions of stimulus response causality. Stimulus-response theory can approximate the relationship between disturbance and action, but it can't predict the consequences of behavior. These consequences are maintained despite disturbances.
There is much we can learn from the development of qualitative relationships models though once we begin to ask questions like how long, how much, when, etc., a qualitative most is not likely to be of much use. The following video demonstrates how, in a very simple goal-seeking structure with delay, depending on the delay, it can be almost impossible to intuit the implications of the interactions with any level of accuracy. The difficulty arises essentially from operating with outdated data. See also Archetypes.
This model was started at the STIA+ Conference in Seattle on April 18th by Rebecca Niles of Leverage Networks for discussion at her Open Space session. The intent is to continue that open space here in a virtual context.
Through our endeavors we have identified and experimented with a number of environments that seem to satisfy the Web Based, Multi-User and Free requirements and seem well up to the task. It seems that while each environment has its strengths there are additional features we would like to see in each one that would enhance their utility.
The city of Bergen has a goal of becoming fossil-free in 2030. How do we get there? Some weeks ago, local experts from different domains came together and developed a causal loop diagram (CLD). This will form the skeleton for the modelling hackathon.
The limits to results structure endeavors to bring a balance between a current state and a desired state though more often than not the action is limited by some constraint. See also Archetypes.
A small change in one variable can have a marked impact on multiple variables. Run the model (with height=0) and consider the output. What happens if you change to height=5. Run the model to find out. Was the change what you expected?
A Tragedy of the Commons situation exists whenever two or more activities, each, which in order to produce results, rely on a shared limited resource. Results for these activities continue to develop as long as their use of the limited resource doesn't exceed the resource limit. Once this limit is reached the results produced by each activity are limited to the level at which the resource is replenished. See also Archetypes.
The Accidental Adversaries structure represents a situation where two interacting entities which should produce growth unwittingly limit the growth of each other because of their actions to promote their own growth. See also Archetypes.
