A lift zonoid criterion is proven to be necessary and sufficient for ranking signals in multi-task agency models, and can be applied to a broader set of signals than a multivariate MPS criterion. The two criteria coincide under certain conditions

In a general agency model with a risk-averse principal, we compare signals on two dimensions–their efficiencies at providing incentives for the agent's effort and efficiencies at conveying inference of the outcome. In order to tackle the moral hazard problem, the standard first order approach...