Dynamics describe how one node influences another: in other words, any causal relationship within your system is a dynamic. Note that one node can influence another in two ways – positive and negative – and the effect can be immediate, or delayed:

Positive influence

A + B

More of A leads to more of B

Examples:
Prevalence of mobile phones leads to more access to pricing information for smallholder farmers.

Spending on advertising leads to more sales.

Negative influence

A - B

More of A leads to less of B

Examples:
Rainy days in summer lead to lower sales of ice cream.

Spending on software leads to less time spent on billing customers.

Delays

A delay B

A changes B, but after some time

Examples:
Malnutrition during childhood leads to mental stunting in adults.

A decline in sales this month will be reflected in inventories next month.

Common confusions:

  • All dynamics are either positive or negative – and the delay just adds a timescale modifier.
  • Positive doesn’t mean ‘good’ and negative doesn’t mean ‘bad’ – it just indicates the direction of the influence.