<http://lib.cnfolio.com/ENG400CausalLoopDiagrams>
Writing and Research in the Workplace

## Causal loop diagrams

Causal loop diagrams (CLD) encourage analysis that emphasize non-linear feedback relationships.

Tragedy of the Commons is a pattern of behaviour was initially described in 1833 by William Forster Lloyd (economist) and later made famous by an article published by Garrett Hardin (ecologist) in 1968. The pattern shows these characteristics:
1. When there is a commonly shared resource, users tend to notice the benefits provided by the resource more than they notice damage to the resource casued by overuse or abuse
2. The consequence of overusing or abusing the resource is that it gradually becomes unusable or unavailable
3. Overuse of the resource is often caused by to increasing competition and lack of cooperation between users of the resource
4. Communal ownership or shared resources often face difficulty with the sharing and enforcement of responsibilities for upkeep and maintenance

### Key steps of CLD analysis

1. Select an issue/question/problem
2. Identify relevant variables that change over time
3. Use arrows to show the direction of influence between variables
4. Connect all variables to create meaningful closed loops
5. Analyze in small incremental steps

### Key steps of CLD analysis

1. Select an issue/question/problem
• Select a scope that is large enough to have sufficient data for analysis, but,
• Keep the scope small enough that it can be solved!
2. Identify relevant variables that change over time
3. Use arrows to show the direction of influence between variables
4. Connect all variables to create meaningful closed loops
5. Analyze in small incremental steps

### Key steps of CLD analysis

1. Select an issue/question/problem
2. Identify relevant variables that change over time
• Names of variables must be a noun or phrase containing a noun
• Variables must be a value that can be measured!
• Values must change over time!
3. Use arrows to show the direction of influence between variables
4. Connect all variables to create meaningful closed loops
5. Analyze in small incremental steps

### Key steps of CLD analysis

1. Select an issue/question/problem
2. Identify relevant variables that change over time
3. Use arrows to show the direction of influence between variables
• A positive sign [+] indicates that two variables change in the same manner, i.e. an increase to A will cause an increase to B and a decrease to A will cause a decrease to B
• A negative sign [–] indicates that two variables change in the opposite manner, i.e. an increase to A will cause a decrease to B and a decrease to A will cause an increase to B
4. Connect all variables to create meaningful closed loops
5. Analyze in small incremental steps

### Key steps of CLD analysis

1. Select an issue/question/problem
2. Identify relevant variables that change over time
3. Use arrows to show the direction of influence between variables
4. Connect all variables to create meaningful closed loops
• A reinforcing loop has an even number of negative causal links and is marked with an R symbol
• A balancing loop has an odd number of negative causal links and is marked with a B symbol
5. Analyze in small incremental steps

### Key steps of CLD analysis

1. Select an issue/question/problem
2. Identify relevant variables that change over time
3. Use arrows to show the direction of influence between variables
4. Connect all variables to create meaningful closed loops
5. Analyze in small incremental steps
• Reinforcing loops lead to exponential rates of change
• When providing a beneficial outcome, reinforcing loops are referred to as a virtuous circle that lead to exponential growth
• When providing a damaging outcome, reinforcing loops are referred to as a vicious circle that lead to exponential decay
• Balancing loops can exist as a point of equilibrium or as a repeating cycle
• It is a common mistake to see the downward part of a cycle as a vicious circle, or the upward part of a cycle as a virtuous circle
• Watch out for delays between variables, which may be indicated with 2 short lines across the arrow of influence
• Important delays between variables may be difficult to detect!

Tragedy of the Commons is a pattern of behaviour was initially described in 1833 by William Forster Lloyd (economist) and later made famous by an article published by Garrett Hardin (ecologist) in 1968. The pattern shows these characteristics:
1. When there is a commonly shared resource, users tend to notice the benefits provided by the resource more than they notice damage to the resource casued by overuse or abuse
2. The consequence of overusing or abusing the resource is that it gradually becomes unusable or unavailable
3. Overuse of the resource is often caused by to increasing competition and lack of cooperation between users of the resource
4. Communal ownership or shared resources often face difficulty with the sharing and enforcement of responsibilities for upkeep and maintenance