{"title":"Permutation-invariant social welfare orders are anonymous","authors":"Jeremy Goodman","doi":"10.1016/j.jmateco.2025.103153","DOIUrl":"10.1016/j.jmateco.2025.103153","url":null,"abstract":"<div><div>We consider two widely discussed impartiality criteria for social welfare relations: Permutation Invariance, which says that every permutation of the population induces an automorphism of the relation, and Anonymity, which says that every permutation of the population induces a permutation that maps every social welfare distribution to one that is equally good. We show that these criteria are equivalent for social welfare orders (i.e., complete social welfare relations). The new result is that Permutation Invariance entails Anonymity for infinite populations. This is not a curiosity, as there are principled reasons (to do with upholding Pareto criteria) that have led many authors to reject Anonymity in favor of Permutation Invariance specifically in the case of infinite populations. A corollary of the present result is that such approaches are incompatible with the use of social welfare orders.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"120 ","pages":"Article 103153"},"PeriodicalIF":0.7,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144780761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unknottedness of graphs of pairwise stable networks & network dynamics","authors":"Julien Fixary","doi":"10.1016/j.jmateco.2025.103155","DOIUrl":"10.1016/j.jmateco.2025.103155","url":null,"abstract":"<div><div>We extend Bich–Fixary’s topological structure theorem about graphs of pairwise stable networks. Specifically, we show that certain graphs of pairwise stable networks are not only homeomorphic to their underlying space of societies but are, in fact, ambient isotopic to a trivial copy of this space. This result aligns with Demichelis–Germano’s unknottedness theorem and Predtetchinski’s unknottedness theorem. Furthermore, we introduce the notion of network dynamics which refers to families of vector fields on the set of weighted networks whose zeros correspond to pairwise stable networks. We leverage our version of the unknottedness theorem to demonstrate that most network dynamics can be continuously connected to one another without introducing additional zeros. Finally, we show that this result has a significant consequence on the indices of these network dynamics at any pairwise stable network — a concept that we connect to genericity using Bich–Fixary’s oddness theorem.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"120 ","pages":"Article 103155"},"PeriodicalIF":1.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Monotonicity in Ultimatum Bargaining","authors":"Jack Robles","doi":"10.1016/j.jmateco.2025.103154","DOIUrl":"10.1016/j.jmateco.2025.103154","url":null,"abstract":"<div><div>We study ultimatum bargaining games with asymmetric information regarding disagreement payoffs. Results from Mensch (2020a) are used to find conditions under which a monotonic Perfect Bayesian Equilibrium exists in these games. A standard single crossing assumption implies the existence when the action space is discrete. Stronger assumptions are required when continuum demands are allowed.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"120 ","pages":"Article 103154"},"PeriodicalIF":1.0,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leonidas Enrique de la Rosa, Nikolaj Niebuhr Lambertsen
{"title":"Overconfidence and moral hazard without commitment","authors":"Leonidas Enrique de la Rosa, Nikolaj Niebuhr Lambertsen","doi":"10.1016/j.jmateco.2025.103145","DOIUrl":"10.1016/j.jmateco.2025.103145","url":null,"abstract":"<div><div>We examine the implications of overconfidence in a moral hazard setting with limited commitment. Limited commitment is costly because the principal will always renegotiate to the optimal risk-sharing contract after the agent chooses his effort level. This means that no effort level above the minimum can be implemented in pure strategies when the principal and the agent have homogeneous beliefs. With overconfidence, the optimal risk-sharing contract provides payments that increase in outcome to exploit the agent’s overconfidence. The agent anticipates the exploitative contract and willingly chooses higher than minimum effort in equilibrium. Providing the agent rent can increase the slope of the optimal risk-sharing contract and, therefore, expand the set of implementable effort levels. In a mixed-strategy equilibrium, overconfidence simultaneously decreases the risk in the second-best contract and increases the risk in the optimal risk-sharing contract, increasing the probability of high effort in equilibrium.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"119 ","pages":"Article 103145"},"PeriodicalIF":1.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144534984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Revealed preference axioms for endogenous consideration set formation","authors":"Edward Honda , Lintao Ye","doi":"10.1016/j.jmateco.2025.103152","DOIUrl":"10.1016/j.jmateco.2025.103152","url":null,"abstract":"<div><div>We consider a setting in which the consideration sets being formed by a decision maker are observable. We analyze the necessary and sufficient conditions under which the observed sets are consistent with endogenous consideration set formation. In particular, we rationalize the consideration sets as being optimally formed by a decision maker who faces costly attention and is forced to choose a subset of alternatives to pay attention to. We show that axioms similar to those from revealed preference theory allow us to do this. The most general model is characterized by a condition resembling the Strong Axiom applied on a domain of sets rather than individual alternatives. Since the idea of observable consideration sets seems realistic in a random choice framework in which we can interpret zero probability of being chosen as the alternative being omitted from the consideration set, we apply our result to this setting using the Logit model. This results in a representation theorem for a generalized version of the Logit model.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"119 ","pages":"Article 103152"},"PeriodicalIF":1.0,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144534985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Discriminatory Search Deterrence","authors":"Hien Pham","doi":"10.1016/j.jmateco.2025.103151","DOIUrl":"10.1016/j.jmateco.2025.103151","url":null,"abstract":"<div><div>If consumers can either costly acquire product information or make their purchase decision merely based on the information provided by the seller, how should the seller design her pricing and information policies? When the consumers’ search cost is publicly observed, it has been well-established that the seller’s optimal information provision fully deters the consumer from engaging in information acquisition. We show that this is, however, not necessarily true with privately observed search cost. Moreover, when consumers’ search cost is either relatively high or zero, we characterize the seller’s optimal menu of prices and information policies featuring discriminatory search deterrence levels.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"119 ","pages":"Article 103151"},"PeriodicalIF":1.0,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144511058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Present bias: Understanding zero leverage policy and unstable capital structure","authors":"Yuan Li , Tak-Yuen Wong , Siqi Zhao","doi":"10.1016/j.jmateco.2025.103148","DOIUrl":"10.1016/j.jmateco.2025.103148","url":null,"abstract":"<div><div>We develop a dynamic capital structure model for a firm controlled by a present-biased entrepreneur without commitment. For sophisticated entrepreneurs, the costs associated with debt issuance act as a de facto commitment device, steering them towards a “zero-leverage strategy” due to the prohibitive costs associated with repeated debt refinancing. In contrast, naive entrepreneur fails to perceive future refinancing, this erroneous belief undermines the commitment value of debt issuance cost and leads to “unstable capital structure”. Borrower naivete provides an opening for financial intermediaries and creditors to impose increased flotation costs and elevated credit spreads. Our analysis further suggests that implementing covenants tied to financial leverage ratios alongside short-term debt obligations can serve as effective strategies to mitigate the impacts of entrepreneurial naivete.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"119 ","pages":"Article 103148"},"PeriodicalIF":1.0,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Critical capital stock in a continuous-time growth model with a convex-concave production function","authors":"Ken-Ichi Akao , Takashi Kamihigashi , Kazuo Nishimura","doi":"10.1016/j.jmateco.2025.103146","DOIUrl":"10.1016/j.jmateco.2025.103146","url":null,"abstract":"<div><div>A nonconcave growth model may exhibit multiple optimal steady states, with a critical capital stock serving as a threshold. Optimal capital paths originating from stock levels below (above) this threshold converge to lower (higher) optimal steady states. The presence of a critical capital stock elucidates the phenomenon of history-dependent development and carries implications for achieving sustainable development. In a continuous-time model featuring a convex-concave production function, we demonstrate that: (a) the critical capital stock is continuous and strictly increasing in the discount rate; (b) its lower bound is the zero capital stock, while the upper bound lies between the stock levels associated with maximum marginal productivity and maximum average productivity; (c) at the upper bound, the critical capital stock coincides with the higher optimal steady state; and (d) the upper bound approaches the capital stock corresponding to maximum average productivity as the intertemporal elasticity of substitution approaches infinity, and converges to that of maximum marginal productivity as the intertemporal elasticity of substitution tends to 0.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"119 ","pages":"Article 103146"},"PeriodicalIF":1.0,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144481068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Compensated discrete choice and the Slutsky equation","authors":"John K. Dagsvik","doi":"10.1016/j.jmateco.2025.103150","DOIUrl":"10.1016/j.jmateco.2025.103150","url":null,"abstract":"<div><div>This paper analyzes compensated price elasticities and corresponding Slutsky equations for discrete choice models. A remarkable feature of the compensated price elasticities is that they are usually not symmetric, as compensated elasticities with respect to a price increase versus a price decrease may be different. We also clarify how results obtain in this paper and similar results in the literature are related. Finally, selected examples are discussed.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"121 ","pages":"Article 103150"},"PeriodicalIF":0.7,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On three welfare properties of monopoly in bilateral exchange","authors":"Francesca Busetto , Giulio Codognato , Sayantan Ghosal , Damiano Turchet","doi":"10.1016/j.jmateco.2025.103147","DOIUrl":"10.1016/j.jmateco.2025.103147","url":null,"abstract":"<div><div>We establish three welfare properties of the model of monopoly introduced by Busetto et al. (2023), where one commodity is held only by the monopolist, represented as an atom, and the other is held only by small traders, represented by an atomless part. First, we prove that a monopoly allocation is Pareto optimal if and only if it is an allocation which corresponds to an efficiency equilibrium. Second, we reformulate a paradox, due to Shitovitz (1997), to show that for any monopoly allocation there is another core allocation, distinct from both a monopoly allocation or a Walras allocation, which is, utility-wise, advantageous for the monopolist and nonadvantageous for the small traders. Finally, we prove a theorem which shows that monopoly is advantageous for the monopolist and nonadvantageous for each trader in the atomless part with respect to all Walras allocations which are not monopoly allocations.</div></div>","PeriodicalId":50145,"journal":{"name":"Journal of Mathematical Economics","volume":"119 ","pages":"Article 103147"},"PeriodicalIF":1.0,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}