Perusvaihtoehto

Perusvaihtoehto is a term used in Finnish decision analysis and impact assessments to describe the baseline or reference option. It represents the scenario that unfolds if no new measures are implemented beyond existing commitments, policies, and infrastructure. The perusvaihtoehto serves as the standard against which other alternatives are compared in terms of costs, benefits, risks, and environmental or social impacts.

Construction of the perusvaihtoehto typically draws on current conditions: ongoing policy trajectories, existing facilities, demographic and economic trends, and expected consumer or user behavior. It is not a forecast of certainty but a defined point of reference that is revised as conditions change. In practice, it is used in environmental impact assessments, transport and urban planning, energy policy, and cost-benefit or cost-effectiveness analyses to enable incremental evaluation of proposed options.

In evaluation, alternatives are assessed by their additional impacts relative to the perusvaihtoehto. For example, in a transport project, the perusvaihtoehto might be maintaining current roads and service levels, while alternatives could include new roads, rail improvements, or demand-management measures. The comparison often focuses on net present value, environmental effects, and feasibility.

Limitations include reliance on assumptions and data quality, which can influence results. As a baseline, the perusvaihtoehto is a tool for comparing strategies rather than a standalone prediction.