公共服务空间公平性区位问题研究进展与展望

Balancing Service Efficiency and Equality in Location Models:Research Progress and Prospects

兼顾公平与效率的公共服务规划受到学术界、决策者和公众的长期关注。本文从公共服务设施布局规划的角度,对空间公平性区位问题研究进行了回顾和展望。首先,在辨析公共服务公平性概念的基础上,总结了空间公平性的度量指标。其次,根据空间公平性区位问题的建模原理,将建模途径划分为3类:直接使用公平性指标,构建单目标优化模型、多目标优化模型,或带公平性约束条件的优化模型;根据罗尔斯“无知之幕”公平正义性原则,使用有序距离加权函数构建有序中值问题模型;以及遵循社会学“不公平厌恶”原理,构建能够权衡公平与效率的公平聚合目标函数。一般地,能否找到“公平有效”的设施布局方案是空间公平性建模的一般准则,构建严格满足或“弱满足”不公平厌恶聚合函数是区位建模的技术途径。最后,对空间公平性区位建模进行了展望:引入距离阈值,简化有序距离加权函数,并将其一般化;证明了新函数是单调函数,且“弱满足”Pigou-Dalton转移规则;讨论了使用新函数改进P中值问题的可行性。

Efficiency and equity are two most important concepts in public services.Public facility locations play a critical role in the delivery of quality services in a convenient and equitable manner.In this paper,the facility location problems considering efficiency and equity are reviewed,and the further research on equitable aggregation functions is suggested.Firstly,the concepts of service equity,spatial equity,and service efficiency in public services are analyzed.The commonly used indicators of spatial equity are redefined mathematically by introducing the weight of service demand.Secondly,according to the key principles of model formulation,three approaches to handle spatial equity of service in location modeling are briefly summarized.The first approach directly uses one of the inequality indicators,as an objective or a constraint,in the mathematical model.Based on Rawls'fairness principle of"veil of ignorance",the second approach uses a well-designed ordered weighted distance function to construct an order median model.Following the sociological principle of"inequity aversion",the third approach uses equitable aggregation functions that take into account both efficiency and equity concerns.The monotonicity,anonymity,and Pigou-Dalton principles of transfers are the essential standards to formulate an equitable aggregation function.An aggregation function that weakly satisfies monotonicity,or the Pigou-Dalton principle of transfers is also acceptable in facility location modeling.Thirdly,several research directions are suggested to overcome the limitations of existing location models.Based on the concept of spatial envy of service,a general inequity-averse aggregation function,which weakly satisfies the criteria of equitable aggregation,is recommended for public facility location modeling.Theoretical analysis shows that the aggregation function has serval advantages:easy to formulate a new location model,relatively easy to solve the new model,and effective to increase the spatial equity by slightly increasing the average travel distance.Finally,it is encouraged to explore the general relationships between service cost,spatial access to service,and spatial equity,which are fundamental for public service evaluation,improvement,and decision making.