Causal loop diagrams

A brief introduction

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Overview of systems thinking analytical tools

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Example of applying systems thinking approach

“Overview of system dynamics modeling approach”, from: Martinez and Richardson (2013)

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What are causal loop diagrams and why are they useful?

• System dynamics method used to develop a qualitative conceptualization of a system

• Focus on visualizing internal, mental models• Facilitates consensus-building and brainstorming• Can help bring together perspectives and data from

different disciplines• Complements “traditional” data collection and

analysis

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What are causal loop diagrams and why are they useful?

• Emphasis on causality and feedback effects

• Causal loop diagrams indicate the sign and direction of the causality and the type of feedback in the system

• Communication – NOT simulation

• Whether modeling is appropriate depends on the question you are trying to solve

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Paina et al (under review) Dual practice policy in Uganda

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Rwashana et al (2008) Immunization System CLD

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Causal loop diagram components

• Causality: AB• Changes in B are caused by changes in A

• Polarity: + or –• If A and B change in the same direction (either both increase or both

decrease), then polarity is +

• If A and B change in opposite directions, then polarity is –

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Causal loop diagram components

• Feedback loops – a change in the system catalyzes a cascade through other variables to either reinforce or balance the initial change.• Reinforcing feedback loop (vicious or virtuous) – amplifying effect

• Balancing feedback loops – dampening effect

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Causal loop diagram components

• Delays• The effect that A has on B is delayed (||)

• Balancing loops are often self-regulating, experience delays

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Developing a causal loop diagram

• Qualitative and quantitative data collected using rigorous methods• Iterative process for identification of key variables and causal linkages

• E.g. Rwashana’s dynamic systems methodology

• Stage 1 – Problem statement

• Stage 2 – Field studies

• Stage 3 – Model building ***This is where CLDs come in***

• Stage 4 – Case study

• Stage 5&6 – Simulations and Policy analysis

• Participatory modeling and diagram development• Group model building

• E.g. Peter Hovmand’s work (for example (2012) Hovmand - Group Model-Building ‘Scripts’ as a Collaborative Planning Tool)

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