The idea of using supermodularity as a robust stability criterion for Nashefficient mechanisms is not only based on its good theoretical properties, but also on strong experimental evidence. In fact it is inspired by the experimental results of Chen and Plott (1996) and Chen and Tang (1998), where they varied a punishment parameter in the Groves-Ledyard mechanism in a set of experiments and obtained totally different dynamic stability results. In this paper, we review the main experimental findings on the dynamic stability of Nash-efficient public goods mechanisms, examine the supermodularity of existing Nash-efficient public goods mechanisms, and use the results to sort a class of experimental findings. Section 2 introduces the environment. Section 3 reviews the experimental results. Section 4 discusses supermodular games. Section 5 investigates whether the existing mechanisms are supermodular games. Section 6 concludes the paper. 2. A PUBLIC GOODS ENVIRONMENT We first introduce notation and the economic environment. Most of the experimental implementations of incentive-compatible mechanisms use a simple environment. Usually there is one private good x, one public good y, and n ≥ 3 players, indexed by subscript i. Production technology for the public good exhibits constant returns to scale, i.e., the production function f (·) is given by y = f(x) = x/b for some b > 0. Preferences are largely restricted to the class of quasilinear preferences, except Harstad and Marrese (1982) and Falkinger et al. (2000). Let E represent the set of transitive, complete and convex individual preference orderings, i , and initial endowments, ω x i. We formally define EQ as follows.