Social Choice and Welfare最新文献

Padding is the practice of adding nonvoters (e.g., noncitizens or disenfranchised prisoners) to an electoral district in order to ensure that the district meets the size quota prescribed by the one man, one vote doctrine without affecting the voting outcome in the district. We show how padding— and its mirror image, pruning—, can lead to arbitrarily large deviations from the socially optimal composition of elected legislatures. We solve the partisan districter’s optimal padding problem.

We consider the two-sided many-to-one matching problem and introduce a class of preferences reflecting natural forms of complementarities. For example, academic departments hire seniors and then supporting juniors, teams recruit different roles and specialties, starting with the critical ones, and firms hire workers at various levels, starting with the executives. The key feature is that a firm can partition workers into types and prioritize certain types before others. Despite this partitionability requirement of choice functions being weaker than substitutes—an essential condition concerning the existence of a stable assignment—we show that it still guarantees the existence of a stable assignment and is further a maximal domain for such.

In an environment with private information, we study the class of sequencing problems with welfare lower bounds. The “generalized welfare lower bound” represents some of the lower bounds that have been previously studied in the literature. Every agent is offered a protection in the form of a minimum guarantee on their utilities. We provide a necessary and sufficient condition to identify an outcome efficient and strategyproof mechanism that satisfies generalized welfare lower bound. We then characterize the entire class of mechanisms that satisfy outcome efficiency, strategyproofness and generalized welfare lower bound. These are termed as “relative pivotal mechanisms”. Our paper proposes relevant theoretical applications namely; ex-ante initial order, identical costs bound and expected cost bound. We also give insights on the issues of feasibility and/or budget balance.

Previous literature has shown that voters’ biased beliefs regarding policy outcomes incentivize the selection of seemingly better, but socially worse, policies. It has also shown that voters’ tendency to gauge an incumbent’s competence by the present state of the economy (retrospective voting) could counteract biased beliefs. In this article, we argue that, when the advantageous consequences of a measure of policy only accrue with considerable lag (the down-up problem), retrospective voting instead amplifies the effects of biased beliefs. Still, we find that it may nevertheless be optimal for an incumbent to select good long-term policies if the incumbent is strongly motivated by the success of the chosen policies. Finally, we investigate the robustness of these conclusions by considering an incumbent bias, limited accountability, and the introduction of incentive and threshold contracts.

The role of patent pools—one-stop systems that gather patents from multiple patent holders and offer them to users as a package—is gaining research attention. To bolster the scarce stream of the literature that has addressed how a patent pool agent distributes royalty revenues among patent holders, we conduct an axiomatic analysis of sharing rules for royalty revenue derived from patents managed by a patent pool agent. In our framework, the patent pool agent organizes the patents into some packages, which we call a package structure. By using the hypergraph formulation developed by van den Nouweland et al. (Int J Game Theory 20:255–268, 1992), we analyze sharing rules that consider the package structure. In our study, we propose a sharing rule and show that it is the unique rule that satisfies efficiency, fairness, and independence requirements. In addition, we analyze sharing rules that enable a patent pool agent to organize a revenue-maximizing and objection-free profile.

We investigate sequential two-stage admission systems with public and private schools. A sequential notion of truthfulness, called straightforwardness, is introduced. Contrary to one-stage systems, sequentiality leads to a trade-off between the existence of a straightforward equilibrium and non-wastefulness. We identify the unique set of rules for two-stage systems that guarantees the existence of a straightforward equilibrium and reduces waste. Existing admission systems in Türkiye and Sweden are analyzed within our general framework.

Universal self-selectivity of a social choice function (SCF) F defined in Koray (Econometrica 68:981–995, 2000) implies that F is either dictatorial or anti-dictatorial. In an attempt to escape this impossibility, here we weaken self-selectivity of an SCF by introducing the notion of selection-closedness pertaining to families of SCFs. As in the self-selectivity setting, a society, which is to make a choice from a set A of alternatives, is also to choose the choice rule that will be employed in making that choice. Self-selectivity of an SCF F requires that F outrivals all available SCFs by selecting itself from among them if it is also used in choosing the choice rule, where the societal preferences on the available SCFs are induced from those on the set A of alternatives in a consequentialist way. Given a collection ({mathscr {F}}) of SCFs and a nonempty finite set ({mathcal {A}}) of available SCFs containing also members of ({mathscr {F}},) an SCF in ({mathscr {F}} cap {mathcal {A}}) is now not required any more to select itself from ({mathcal {A}},) but it suffices that it selects some member of ({mathscr {F}}) for ({mathscr {F}}) to be selection-closed. It is shown that a proper subset of the collection of all neutral SCFs is selection-closed if and only if all its members are either dictatorships or anti-dictatorships. We further weaken the notion of selection-closedness to an extent that not only enables us to escape the impossibility result, but also equips us with a yardstick to compare correspondences as to whether or not their singleton valued refinements form a weakly selection-closed family. A rich family of scoring correspondences with strict scoring vectors are shown to pass the test of weak selection-closedness, while the Pareto and Condorcet correspondences fail.

Judgment-aggregation theory has always focused on the attainment of rational collective judgments. But so far, rationality has been understood in static terms: as coherence of judgments at a given time, defined as consistency, completeness, and/or deductive closure. This paper asks whether collective judgments can be dynamically rational, so that they change rationally in response to new information. Formally, a judgment aggregation rule is dynamically rational with respect to a given revision operator if, whenever all individuals revise their judgments in light of some information (a learnt proposition), then the new aggregate judgments are the old ones revised in light of this information, i.e., aggregation and revision commute. We prove an impossibility theorem: if the propositions on the agenda are non-trivially connected, no judgment aggregation rule with standard properties is dynamically rational with respect to any revision operator satisfying some basic conditions. Our theorem is the dynamic-rationality counterpart of some well-known impossibility theorems for static rationality. We also explore how dynamic rationality might be achieved by relaxing some of the conditions on the aggregation rule and/or the revision operator. Notably, premise-based aggregation rules are dynamically rational with respect to so-called premise-based revision operators.

We revise a result positing that there is a positive relationship between contributions and welfare in a public good provision game under price uncertainty (Gradstein et al. Soc Choice Welf 10(4):371–382, 1993). The authors state in Proposition 3 that welfare decreases when price uncertainty induces a reduction in private contributions. By contrast, we show that, under certain conditions, a reduction in contributions can be associated with an improvement in consumer welfare. This result is important because public policy regarding the provision of public goods is often based on indicators such as citizen participation, which, as this note shows, may constitute a misleading signal.

Are there group decision methods which (i) give everyone, including minorities, an equal share of effective decision power even when voters act strategically, (ii) promote consensus and equality, rather than polarization and inequality, and (iii) do not favour the status quo or rely too much on chance? We describe two non-deterministic group decision methods that meet these criteria, one based on automatic bargaining over lotteries, the other on conditional commitments to approve compromise options. Using theoretical analysis, agent-based simulations and a behavioral experiment, we show that these methods prevent majorities from consistently suppressing minorities, which can happen in deterministic methods, and keeps proponents of the status quo from blocking decisions, as in other consensus-based approaches. Our simulations show that these methods achieve aggregate welfare comparable to common voting methods, while employing chance judiciously, and that the welfare costs of fairness and consensus are small compared to the inequality costs of majoritarianism. In an incentivized experiment with naive participants, we find that a sizable fraction of participants prefers to use a non-deterministic voting method over Plurality Voting to allocate monetary resources. However, this depends critically on their position within the group. Those in the majority show a strong preference for majoritarian voting methods.