The existence of anonymous, stationary, monotone social welfare functions satisfying restricted dominance: an answer to an open question in intergenerational equity

In this note, we consider social welfare functions on infinite utility streams and answer an open question posed in Asheim et al (2021, Remark 1). There exists a real-valued representation of social welfare preferences that satisfies monotonicity, stationarity, restricted dominance, and strong anonymity, hence also finite anonymity. Our social welfare function satisfies a stronger finite-rank sensitivity condition, Liminf-Restricted Dominance, in the sense of Asheim et al. (2022) and Asheim et al. (2025). Our construction shows that limited discontinuity is not redundant in Asheim et al. (2021, Proposition 2): once that diagonal continuity condition is dropped, even arbitrary-permutation invariance can coexist with stationarity and non-trivial sensitivity.