 where \(\Psi \big(f(s),g(s)\big)\) is defined as \(M\big(f(s),g(s)\big)-M\big(g(s),f(s)\big)\). This quantity thus corresponds to the net balance of regret/rejoicement associated with choosing \(f\) over \(g\) in states \(s\). Depending on the properties of \(\Psi\), decision makers can be characterised as being ‘regret-neutral’, ‘regret-averse’ or even ‘regret-seeking’. Regret neutrality corresponds to the case in which, for all \(x_1,x_2,x_3\in \mathcal{X}\),