Vetoschwelle

Vetoschwelle, or veto threshold, is a term used in political science to describe the level of policy change or the configuration of political actors needed for a proposal to be blocked by one or more veto players. In veto player theory, developed to analyze how institutional rules shape policy outcomes, a veto player is an actor whose consent is necessary for any change. The vetoschwelle refers to the boundary in the policy space that must be satisfied for a reform to pass, given the positions of all veto players and the decision rules in place.

Practically, the vetoschwelle corresponds to the intersection of the acceptance ranges of all veto players under the applicable decision rule (for example, unanimity, supermajority, or qualified majority with veto constraints). If a proposed policy lies outside this intersection, at least one veto player can block it. Thus the vetoschwelle determines how large a reform can be without triggering a veto.

Factors shaping the Vetoschwelle include the number of veto players, their ideological distances, and the formal rules governing decision making. More veto players or greater dispersion of positions tend to raise the threshold, increasing the difficulty of reform and the stability of the status quo. Conversely, convergence among veto players or more permissive decision rules lower the threshold and facilitate reforms.

The concept is used to analyze legislative bargaining, constitutional design, and policy stability in federations and unions, including the European Union and national parliaments. Related concepts include veto power, veto players, and the policy space.