The politics of baselines: A political feasibility framework for energy and climate scenarios

Energy, transport, and climate scenarios rely on assumptions about future taxes, subsidies, and regulations, but such policy trajectories are rarely screened for political feasibility before they enter models. This paper addresses this often-neglected step in scenario design by developing a political feasibility framework to help modellers define and compare contested policy trajectories before quantification. Building on the distinction between outside and inside views of feasibility, the framework proceeds in two steps. First, it scopes a limited set of plausible trajectories using historical precedent, institutional practice, and actor commitments. Second, it evaluates them across five feasibility dimensions informed by institutional theory and political economy. The framework is demonstrated using a Swedish rail-demand forecast from 1999, in which a flat real road fuel tax path was used in the adopted-policy baseline. The case illustrates how seemingly neutral baseline assumptions embed political judgements and how a structured feasibility assessment can make alternative policy trajectories explicit and comparable. A simplified demand model is used to simulate the effect of alternative tax trajectories on rail demand. The framework offers scenario teams and modellers a practical approach to selecting and documenting policy assumptions based on political feasibility across adopted-policy, planned-policy, and exploratory scenario settings.