{"title":"Optimizing university restructuring for targeted knowledge output: A preliminary evaluation of Chinese university mergers incorporating preferences","authors":"Jiajia Zhao, Michael Vardanyan, Zhiyang Shen","doi":"10.1016/j.ejor.2025.08.062","DOIUrl":"https://doi.org/10.1016/j.ejor.2025.08.062","url":null,"abstract":"Chinese universities have experienced a significant wave of mergers since the late 1990s, raising questions about the impact of such consolidation on the knowledge output efficiency and economies of scale and scope in higher education. In this study, we propose a nonparametric model that takes into account specific output preferences during a preliminary evaluation of merger proposals. Additionally, our model addresses the challenges related to the existence of infeasible solutions that have been highlighted in related literature. Empirical analysis using a sample of Chinese research universities suggests that the current number of universities is below optimal in most provinces regardless of the type of knowledge outcome used to assess university performance. This suggests that further university mergers are unnecessary in these regions. However, multiple beneficial merger scenarios still exist in the provinces of Guizhou and Gansu. In Guizhou, some merger plans could lead to efficiency gains when scholarly publications are used as the knowledge outcome, while in Gansu, several consolidation scenarios show potential gains when research projects serve as outputs. Moreover, we found evidence of widespread diseconomies of scale across most merger scenarios along with relatively modest economies of scope within these two provinces.","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"131 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elena Bárcena-Martín, Francisca García-Pardo, Mariano Luque, Ana B. Ruiz, Francisco Ruiz
{"title":"A Relative Distance-based Scalarization Scheme using Reference Levels","authors":"Elena Bárcena-Martín, Francisca García-Pardo, Mariano Luque, Ana B. Ruiz, Francisco Ruiz","doi":"10.1016/j.ejor.2025.09.001","DOIUrl":"https://doi.org/10.1016/j.ejor.2025.09.001","url":null,"abstract":"When variables measured in different units are used to analyze a given phenomenon, it is usually necessary to scale these variables in order to bring all of them down to a common scale. This allows their subsequent aggregation into a single measurement. This is the case, for example, of the processes of constructing composite indicators from a system of simple indicators. One way to perform this scaling is through distance-based schemes, used when reference levels are available for the different variables, which allow defining different performance bands. In these cases, the scaling function is often called the achievement scalarizing function. However, the linear nature of the achievement scalarizing function employed so far implies that the achievement level of each entity is scalarized in absolute terms, that is, considering their absolute distance to the reference levels, without considering the distribution of achievement values across all considered entities. In this paper, we propose a new achievement scalarizing function based on reference levels. This new function encompasses formulations that allow for the inclusion of relative assessments. Thus, we seek to broaden the application scope of distance-based scalarizations to analyze societal aspects where it is crucial to compare the performances of the entities not only with respect to the reference levels, but also with respect to the performances achieved by other entities. Finally, since absolute or relative measures may be required for different values when scaling the same variable, we propose a more general hybrid scheme that allows the combination of both schemes.","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"31 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Productivity dynamics, innovation and endogeneity: A semiparametric stochastic frontiers approach","authors":"Fikru K. Alemayehu, Kai Sun, Subal C. Kumbhakar","doi":"10.1016/j.ejor.2025.08.028","DOIUrl":"https://doi.org/10.1016/j.ejor.2025.08.028","url":null,"abstract":"This research investigates how innovation influences productivity and technical efficiency in the service industry. We apply a novel approach that addresses endogeneity and heterogeneity of environmental variables in the semiparametric smooth coefficient stochastic frontier model framework. For this purpose, we use instruments such as market channels, collaborative innovation efforts, public subsidies, and spending on innovation. Our study relies on data from the Community Innovation Survey (CIS) and corporate financial records spanning from 2003 to 2020 in Norway. The findings show a U-shaped direct influence of innovation on productivity (i.e., through total factor productivity), complemented by positive indirect effects (i.e, via inputs) and negative impacts on the efficiency of firms within the Norwegian service sector. The research highlights the diverse impact of innovation across firms and sectors within the service industry, revealing significant heterogeneity in its effects. These findings are crucial for managers and policymakers who want to promote innovation, enhance productivity and efficiency in services, and stimulate innovation-driven growth.","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"50 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thomas Masanet, Benoît Audry, Christian Jacquelinet, Pascal Moyal
{"title":"Toward organ shortage resilient allocation policies using real-time queueing models for liver transplantation","authors":"Thomas Masanet, Benoît Audry, Christian Jacquelinet, Pascal Moyal","doi":"10.1016/j.ejor.2025.07.030","DOIUrl":"10.1016/j.ejor.2025.07.030","url":null,"abstract":"<div><div>We report in this paper on the potential interest of real-time queueing models to optimize organ allocation policies. We especially focus on building organ shortage resilient policies in terms of equity, as we experienced differential impact of the COVID epidemic organ shortage on transplant access, according to the cause of liver failure. Patient’s death on the waiting list or dropout for being too sick, resulting from the absence of a timely available organ, is chosen as the main equity metric. Results obtained with the composite allocation score used in France is challenged against the so-called Early Simulated Deadline First (ESDF) real-time queueing discipline, under increasing levels of organ shortage, by extensive simulations. The ESDF policy is a variant of the well-know Earliest Deadline First (EDF) policy, which was shown as optimal in various contexts in the queueing literature. In the present case, the time to the deadline represents the remaining life duration of patients — which is of course unknown. So we propose to simulate a fictional life-duration, and give priority to the earliest simulated deadline. This leads to a simple and comprehensive representation of the system at hand by a Markov process. Our simulation results clearly show that the ESDF policy allows to maintain equity between indications, conversely to the scoring policy, which was not resilient to increasing levels of organ shortage.</div></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"328 3","pages":"Pages 1054-1067"},"PeriodicalIF":6.0,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145289950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Strategic inventory of original products amid new product launches","authors":"Chenglin Ma, Hubert Pun, Ruiqing Zhao","doi":"10.1016/j.ejor.2025.08.052","DOIUrl":"https://doi.org/10.1016/j.ejor.2025.08.052","url":null,"abstract":"Some suppliers adopt a single rollover strategy to periodically introduce new or updated products while phasing out the original versions; however, their retailers may strategically carry the discontinued old products after the launch of the new product. This paper demonstrates the interaction between <ce:italic>product innovation</ce:italic> and <ce:italic>strategic inventory</ce:italic> in a bilateral monopoly framework. We model a supplier that sequentially sells two product versions (original and updated) to a retailer in two periods. The supplier determines the innovation level of updated products, and the retailer may carry original products which are exclusively supplied in period 1 to period 2. We find that increased inventory holding costs, which reduce the retailer's incentive to stock the original product, may negatively impact innovation for the updated product but benefit the supply chain members. In addition, due to the supplier’s ability to innovate, the retailer's strategic inventory leads to an uncommon lose-lose situation for both the supplier and the retailer when the inventory holding cost is high, a result which deviates from the strategic inventory literature. Our research suggests that policymakers should use appropriate inventory taxes and subsidies to maintain moderate inventory holding costs in order to foster innovation. Moreover, suppliers should strategically manage retailer inventory costs through customized storage and subsidy contracts to maximize profitability. Lastly, to avoid the lose-lose scenario caused by strategic inventory, supply chain members should consider arranging prior commitments to not hold inventory or employ the use of Vendor Managed Inventory (VMI).","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"28 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Import duty payment options for the parallel import channel: Duty-inclusive strategy versus duty-recovery strategy","authors":"Li Hu, Qin Zhou, Li Wang, Xiangyu Zhou","doi":"10.1016/j.ejor.2025.08.017","DOIUrl":"https://doi.org/10.1016/j.ejor.2025.08.017","url":null,"abstract":"Many multinational manufacturers are expanding cross-border markets via authorized resale and parallel import channels. Unlike purchases made through authorized resale channels, consumers opting for parallel import channels encounter lower prices but face import duty issues and extended waiting times. Two primary payment strategies are typically adopted in parallel import channels to address import duties: one charges consumers the retail price along with import duties upfront (known as the duty-inclusive strategy), while the other charges only the retail price, with import duties pursued by Customs if the products are inspected (defined as the duty-recovery strategy). Despite its practical significance, this issue remains underexplored in the literature. This study develops a game-theoretic model to investigate the impact of duty payment strategies on dual-channel competition. Our analysis yields three main findings. First, a parallel importer will adopt the duty-recovery strategy when the additional waiting time due to back duties is limited. This strategy can ease price competition between the two channels, resulting in a joint increase in retail prices. Second, when the additional waiting time is moderate, the duty-inclusive strategy can benefit the parallel importer, authorized retailer, and manufacturer simultaneously. Third, the duty-recovery strategy enables consumers to potentially evade import duties, which results in a loss of government tariff revenue and, in most cases, a reduction in overall consumer surplus. To address this issue, this paper proposes a punitive tariff mechanism designed to induce parallel importers to abandon the duty-recovery strategy.","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"130 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A primal–dual policy iteration algorithm for constrained Markov decision processes","authors":"Zeyu Liu , Xueping Li , Anahita Khojandi","doi":"10.1016/j.ejor.2025.08.038","DOIUrl":"10.1016/j.ejor.2025.08.038","url":null,"abstract":"<div><div>The solution algorithms of Constrained Markov Decision Process (CMDP), a widely adopted model for sequential decision-making, have been intensively studied in the literature. Despite increasing effort, the Linear Programming (LP) formulation of CMDP remains the dominant exact method that leads to the optimal solution without constraint violations. However, the LP formulation is computationally inefficient due to the curse of dimensionality in CMDP state and action spaces. In this study, we introduce a novel policy iteration method for CMDP, based on decomposition and row-generation techniques. We design a Primal–Dual Policy Iteration (PDPI) algorithm that utilizes state values and Lagrangian multipliers to improve randomized stationary policies in an iterative fashion. We analytically show that upon convergence, PDPI produces the optimal solution for CMDP. An upper bound of the convergence iterations is also given. To validate the algorithm performance, we conduct comprehensive computational experiments on six benchmarking problems curated from the literature. Results show that PDPI outperforms conventional methods considerably, improving the total algorithm runtime by up to 89.19%. The improvement becomes more significant as the problem size grows larger. We further provide insights and discuss the impact of the developed method.</div></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"328 1","pages":"Pages 174-188"},"PeriodicalIF":6.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144923968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Cesarone, M. Corradini, L. Lampariello, J. Riccioni
{"title":"A new behavioral model for portfolio selection using the Half-Full/Half-Empty approach","authors":"F. Cesarone, M. Corradini, L. Lampariello, J. Riccioni","doi":"10.1016/j.ejor.2025.08.040","DOIUrl":"https://doi.org/10.1016/j.ejor.2025.08.040","url":null,"abstract":"We focus on a behavioral model that has been recently proposed in the literature, whose rationale can be traced back to the Half-Full/Half-Empty glass metaphor. More precisely, we generalize the Half-Full/Half-Empty approach to the context of positive and negative lotteries and give financial and behavioral interpretations of the Half-Full/Half-Empty parameters. We develop a portfolio selection model based on the Half-Full/Half-Empty strategy, resulting in a nonconvex optimization problem, which, nonetheless, is proven to be equivalent to an alternative Mixed-Integer Linear Programming formulation. Based on three real-world datasets, we obtain empirical validation of the theoretical properties of the Half-Full/Half-Empty model, and the computational results highlight the versatility of our approach when varying its defining parameter values.","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"16 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144923967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Problem of locating and allocating charging equipment for battery electric buses under stochastic charging demand","authors":"Sadjad Bazarnovi, Taner Cokyasar, Omer Verbas, Abolfazl (Kouros) Mohammadian","doi":"10.1016/j.ejor.2025.07.064","DOIUrl":"https://doi.org/10.1016/j.ejor.2025.07.064","url":null,"abstract":"Bus electrification is an important consideration in urban transportation systems. Battery Electric Buses (BEBs), however, often need recharging, making the Problem of Locating and Allocating Charging Equipment for BEBs (PLACE-BEB) essential for efficient operations. This study proposes an optimization framework to solve the PLACE-BEB by determining the optimal placement of charger types at potential locations under the stochastic charging demand. Leveraging the existing stochastic location literature, we develop a Mixed-Integer Non-Linear Program (MINLP) to model the problem. To solve this problem, we develop an exact solution method that minimizes the costs related to building charging stations, charger allocation, travel to stations, and average queueing and charging times. Queueing dynamics are modeled using an <ce:italic>M</ce:italic>/<ce:italic>M</ce:italic>/<ce:italic>s</ce:italic> queue, with the number of servers at each location treated as a decision variable. To improve scalability, we implement a Simulated Annealing (SA) and a Genetic Algorithm (GA) allowing for efficient solutions to large-scale problems. The computational performance of the methods was thoroughly evaluated, revealing that SA was effective for small-scale problems, while GA outperformed others for large-scale instances. A case study comparing garage-only, other-only, and mixed scenarios, along with joint deployment, highlighted the cost benefits of a collaborative and a comprehensive approach. Sensitivity analyses showed that the waiting time is a key factor to consider in the decision-making.","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"34 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Share or not share capacity? Target customer type in batch service queue systems","authors":"Kenan Li, Zhaotong Lian, Xin Li","doi":"10.1016/j.ejor.2025.08.012","DOIUrl":"https://doi.org/10.1016/j.ejor.2025.08.012","url":null,"abstract":"This study examines the behaviour of two service companies under the M/M<mml:math altimg=\"si1.svg\" display=\"inline\"><mml:msup><mml:mrow></mml:mrow><mml:mrow><mml:mrow><mml:mo>[</mml:mo><mml:mi>n</mml:mi><mml:mo>]</mml:mo></mml:mrow></mml:mrow></mml:msup></mml:math>/1 batch service queueing model, which divides their customers into brand-loyal and searching categories. Our research indicates that when market conditions are highly competitive and the rewards for different types of customers are similar, these firms primarily cater to brand-loyal customers in very large or very small markets. However, when the market is moderate, they expand their customer base to include all types. It is worth noting that as the difference in rewards between customer groups increases, these firms focus exclusively on brand-loyal customers. In co-opetition, where both companies provide similar services, they aggressively cut prices to attract searching customers. This fierce price competition ultimately drives prices down to marginal cost levels, eliminating the possibility of profit and compelling a strategic pivot back to prioritizing brand-loyal customers. Our research indicates that under co-opetition, firms are more likely to achieve higher revenues in extremely large or small markets. In contrast, in competitive settings, firms tend to secure greater profitability in markets that maintain specific proportions of brand-loyal customers.","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":"20 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}