Scenario analysis

Scenario analysis compares model outcomes under clearly defined alternative assumptions or interventions.

Examples

An epidemic study might compare no intervention, early intervention, delayed intervention and different vaccination rates. An ecological study might compare alternative harvesting or climate conditions.

Scenario is not forecast

A scenario answers a conditional question: what does the model imply if these assumptions hold? It does not necessarily assign a probability that the scenario itself will occur.

Useful comparisons

Compare outcomes using consistent quantities such as peak size, cumulative burden, extinction probability, time above capacity or intervention cost.

Uncertainty within scenarios

Each scenario can still contain parameter and stochastic uncertainty, so results may be distributions rather than single trajectories.