Degree of Causal Contribution and Degree of Moral Responsibility: Using Shapley Values as a Measure

This paper is about the pros and cons of measuring degree of causal contribution by Shapley Value (a concept from cooperative game theory). The Shapley Value approach defines degree of causal contribution for a causal factor in terms of a kind of average of its marginal contributions across a range of possible groupings of factors. Some existing literature already explores applying Shapley Values to degrees of causal contributions. This paper supplements this literature by evaluating a range of justifications for applying Shapley Values, addressing several potential problems for the Shapley Value approach, and tying this to recent discussions of the tension between degree of sufficiency and degree of necessity originating with Bernstein.