Based on an axiomatically derived provision rule allowing community members to endogenously determine which, if any, public project should be provided, we perform experiments where (i) not all parties benefit from provision, and (ii) the projects’ “costs” can be negative. In the tradition of legal mechanism design, the proposed provision rule is widely applicable. Additionally, it relies on intuitive fairness and profitability requirements. Our results indicate that the provision rule is conducive to efficiency, despite its multiplicity of equilibria and un- derbidding incentives. The only condition is that the cost of the most efficient project is positive.