Cone of Plausibility

The cone of plausibility, often called the futures cone, is a framing device for scenario work that projects a baseline 'expected' future and then bounds a widening cone of alternative futures around it by varying the key drivers and assumptions on which that baseline rests. Drawn from the present at the cone's apex, the trajectory fans out as it extends into the future, because uncertainty compounds over time and the range of futures that remain plausible grows wider the further out one looks. Joseph Voros, building on Charles Taylor's earlier cone imagery, formalized the device by nesting categories of futures — possible, plausible, probable, and preferable — within the cone, giving foresight practitioners a shared vocabulary for distinguishing what could conceivably happen from what could reasonably happen and from what is most likely. As Bishop, Hines, and Collins note in their survey of scenario techniques, the cone provides a disciplined way to generate and bound a manageable set of alternative scenarios.