An Axiomatic Approach to Formalized Responsibility Ascription

Quantified responsibility ascription in complex scenarios is of crucial importance in current debates regarding collective action, for example in the face of various environmental crises. Within this endeavor, we recently proposed considering a probabilistic view of causation, rather than the deterministic views employed in much of the previous formal responsibility literature, and presented a corresponding framework as well as initial candidate functions applicable to a range of scenarios. In the current paper, we extend this contribution by formally evaluating the qualities of proposed functions through an axiomatic approach. First, we decompose responsibility ascription into distinct contributing functions, before defining a number of desirable properties, or axioms, for these. Afterwards we evaluate the proposed functions regarding compliance with these axioms. We find an incompatibility between axioms determining upper and lower bounds in one of the contributing functions, imposing a choice for one variant - upper bound or lower bound. For the other contributing function we are able to axiomatically characterize one specific function. As the previously mentioned incompatibility extends to the combined responsibility function we finally present maximally axiom compliant combined functions for each variant - including the upper bound axiom or including the lower bound axiom.