Single and attractive: Uniqueness and stability of economic equilibria under monotonicity assumptions

• 成果类型: Article
• 署名作者: Bifulco, Patrizio; Gluck, Jochen; Krebs, Oliver; Kukharskyy, Bohdan
• 署名单位: Fern University Hagen; University of Wuppertal; Swiss Federal Institutes of Technology Domain; ETH Zurich; City University of New York (CUNY) System; Baruch College (CUNY); Leibniz Association; Ifo Institut
• 刊物名称: JOURNAL OF INTERNATIONAL ECONOMICS
• ISSN/ISSBN: 0022-1996
• DOI: 10.1016/j.jinteco.2025.104187
• 发表日期: 2026
• 关键词: General equilibrium; TRADE; EXISTENCE; gravity; number; GOODS; MODEL

摘要

This paper characterizes equilibrium properties of a broad class of economic models that allow multiple heterogeneous agents to interact in heterogeneous ways across several markets. Our key contribution is a new theorem that provides sufficient conditions for uniqueness, attractivity, and stability of solutions of non-linear equation systems. To illustrate the applicability of our theorem, we characterize the general equilibrium properties of an extended version of the universal gravity framework, which comprises a host of seminal trade models. Specifically, we provide conditions for uniqueness, stability, and attractivity when, in line with real-world observations, (i) supply elasticities are allowed to vary by country, or (ii) multiple sectors are introduced. We also provide a practical toolkit for future research on how our theorem can be applied to establish uniqueness, stability, and attractivity of equilibria in a broad set of economic models.