Is it better to present evidence first or second in trials if witnesses cannot lie, and the litigants share all available witnesses? We address this question by defining preferences over playing games via their equilibrium correspondences. Exploiting this partial ordering over games, we show that litigants cannot prefer to lead, but can prefer to follow; the judge/jury may also prefer some litigant to lead, but only if the litigants each prefer to follow. Allowing a litigant to choose whether to lead after observing the available witnesses does not benefit either that litigant or the judge/jury.

We experimentally investigate, in an unstructured bargaining environment with commonly known money payoffs, the Attraction Effect and Compromise Effect (AE and CE) in bargaining, namely a tendency for bargainers to agree to an intermediate option (CE), or to an option that dominates another option (AE). We conjecture that the relevance of the AE and CE in bargaining is constrained by how focal the feasible agreements' payoffs are. We indeed observe that there are significant AEs and CEs, but these effects are mediated by the efficiency and equality properties of the feasible agreements. Due to the allure of equality, the effects are harder to observe when an equal earnings contract is available. Decoys are more effective in shifting agreements from a very unequal contract to a less unequal one rather than the reverse.

This paper studies an extensive form game of coalition formation with random proposers in games with externalities. It is shown that an agreement will be reached without delay if any set of coalitions profits from merging. Even under this strong condition, the equilibrium coalition structure is not necessarily efficient. There may be multiple equilibria even in the absence of externalities, and symmetric players are not necessarily treated symmetrically in equilibrium. If the grand coalition forms without delay in equilibrium, expected payoffs must be in the core of the characteristic function game that assigns to each coalition its equilibrium payoff. Compared with the rule of order process of Ray and Vohra (Games Econ Behav 26:286–336, 1999), the bargaining procedure with random proposers tends to give a large advantage to the proposer, whereas the bargaining procedure with a rule of order tends to favor the responders. The equilibria of the two procedures cannot be ranked in general in terms of efficiency.

We study the formation of networks in environments where agents derive benefits from their neighbours (immediate links) but suffer losses through contagion when any agent on a path that connects them is hit by a shock. We first consider networks with undirected links (e.g. epidemics, underground resistance organizations, trade networks). We find that the only networks that satisfy strong notions of stability are comprised of disjoint subgraphs that are complete. Then, we consider networks with directed links and we find that stable networks can be asymmetric, connected but not completely connected, thus capturing the main features of production and financial networks. We also identify a trade-off between efficiency and stability.

We investigate a novel way to encourage separation between firms, causing local pollution, and their victims (households): payments from households to distant polluting firms. These payments do not require monitoring of firms' emissions or their abatement costs. In our model, households and firms can choose from two locations (A and B, with A larger than B). Households incur environmental damage from firms in the same location. Under laissez faire, payments from households in one location (say A) to firms in the other location (say B) will prompt firms to move from A to B and to stay there, thus reducing damage to households in A. The maximum that households are willing to pay temporarily is the amount that currently makes them indifferent between A and B. The payments make A less attractive to firms as well as to households. The unique positive-payment equilibrium implements the global welfare optimum where laissez faire does not. We examine from which starting points this payment equilibrium can be reached.