Simple contract class achieving constant-factor approximation

Identify a class of simple contracts (beyond monotone families already ruled out) that guarantees a constant-factor approximation to the principal’s expected utility achieved by optimal contracts in the discrete principal–agent model.

Background

The survey emphasizes the appeal of simple contracts, such as linear and single-outcome payment schemes, for interpretability and robustness. While monotone contract classes cannot achieve constant-factor approximations (per Theorem 6.1 in \cite{DuttingRT19}), it remains open whether another simple class could.

A positive resolution would bridge interpretability and performance, yielding practical contract architectures with provable guarantees.