A one-sided many-to-many matching problem

This study discusses a one-sided many-to-many matching model wherein agents may not be divided into two disjoint sets. Moreover, each agent is allowed to have multiple partnerships in our model. We restrict our attention to the case where the preference of each agent is single-peaked over: (i) the total number of partnerships with all other agents, and (ii) the number of partnerships that the agent has with each of the other agents. We represent a matching as a multigraph, and characterize a matching that is stable and constrained efficient. Finally, we show that any direct mechanism for selecting a stable and constrained efficient matching is not strategy-proof.     

Who shapes network neutrality policy debate? An examination of information subsidizers in the mainstream media and at Congressional and FCC hearings

Recognizing policy-making process as a communicative process, this study examines who has subsidized information relating to the net neutrality policy debate. Empirical data has been collected from net neutrality stories published in four national newspapers, as well as from hearings by Congress and the Federal Communications Commission (FCC), during the period of February 2004 through January 2009. Study findings reveal that corporate interests have played a significant role in subsidizing information on net neutrality, both to the public through the mainstream media and to legislators through Congressional hearings. Furthermore, study results show that experts played a larger role in defining net neutrality through the mainstream media and FCC hearings than they did through Congressional hearings. Finally, the role of advocacy group representatives was more apparent at Congressional hearings than via the other two available information channels.     

A network approach to modeling the multi-echelon spare-part inventory system with backorders and interval-valued demand

A multi-echelon inventory system implies the existence of a hierarchy of stocking locations, and the dependence and interaction between them. We consider a multi-echelon, spare-part inventory management problem with outsourcing and backordering. The problem is characterized by deterministic repair time/cost, and supply and demand that lie within prescribed intervals and that vary over time. The objective is to minimize the total inventory and transportation costs. We develop a network model for problem analysis and present a network flow algorithm for solving the problem. We prove that the Wagner-Whitin property, known for the lot-sizing problem, can be extended to the spare-part inventory management problem under study.     

Smart city networks' governance: The Spanish smart city network case study

The governance of smart city networks emerges as a new research area intersecting smart governance and public networks studies. This work aims to contribute to the literature on smart cities governance by studying councillor's governance in complex networks and on network performance. To carry out this analysis, the Spanish Network of Smart Cities (RECI), one of the first of its kind and an international reference for city networks, is reviewed as a case study, with the main objective of establishing a theory on its global innovation capacity and operations, together with the local level spurring influenced on its members. A PEST (Political, Economic, Social and Technological) analysis was carried out in order to assess the impact of the smart city network both at local, national and international level. This research was completed with a consultation carried out among some of RECI's municipalities. The analysis of the results shows how RECI can be considered an example of a well organised network with quantifiable savings for its members, capable of configuring future policies in local administration, necessarily related to efficiency, digitalization and citizen-centricity and with key topics to build the future. The study also suggests recommendations oriented to potential improvements that smart city networks could undertake.     

Identifying new dimensions of business incubation: A multi-level analysis of Karolinska Institute's incubation system

Relying on an in-depth case study of the incubator related to the Swedish medical university Karolinska Institute's (KI), this paper identifies new analytical and strategic dimensions of incubation. Departing from the current literature's prevalent focus on incubators as organizations performing a predefined set of activities for incubatees (facility renting, coaching, training and connecting), we perform a multilevel analysis embracing, next to the organizational and the project-specific levels, also the broader institutional and inter-organizational level. Our analysis relies on seven key components of incubation, namely its time, place, sources, resources, control/governance, activities/services and outcomes. Further, we view incubators as strategic actors engaged in value creation on a broader arena than the strict incubation context, even an international arena, where incubators' choices and interactions can be analyzed with the help of concepts from various streams in the business strategy literature. The specific strategic drivers of business incubation that we identify in the KI incubator's case are six: positioning in the value chain, risk taking/time perspective, revenue model, governance/control, internationalization, and cooperation/competition. The paper concludes with managerial implications urging incubators to take more of a strategic perspective rather than focussing only on the established components of their operations.     

Global engineering services: Shedding light on network capabilities

This paper addresses the operations challenges of effectively managing professional services on a global scale. The specific context for the study is professional engineering services and particularly those that are delivered globally – global engineering services (GES). Estimates suggest that the market for GES was around US$930 billion in 2012, rising to US$1.4 trillion by 2020 (ISG, 2013). Yet this influential sector receives scant attention in the operations management literature. The paper draws on six case studies to explore the operations management challenges of delivering GES. In doing so the paper introduces the concept of network capabilities for GES, highlighting the centrality that: (i) network resources – accessing and deploying dispersed resources, (ii) network coordination – coordinating and integrating network activities, and (iii) network learning – collective learning and knowledge management, all play in enabling the successful operational management of GES.     

WHICH AGGLOMERATION EXTERNALITIES MATTER MOST AND WHY?

This paper revisits the ongoing discussion on the importance of agglomeration externalities – specifically specialization, diversity and competition effects – that may contribute to innovation, productivity and urban employment growth. Previous meta‐analyses suggested that the evidence on agglomeration externalities is strongly context‐specific. Expanding an earlier analysis of 31 articles, we seek to draw in this paper more robust conclusions by means of the statistical evidence for agglomeration externalities presented in 73 scientific articles, all building on the seminal work of Glaeser et al. (1992). Our results confirm that the heterogeneity among studies is huge and can only be partially accounted for by means of an ordered probit analysis. Additionally, some evidence of publication bias is found. We conclude that the conventional lines of inquiry in this literature may now have reached strongly diminishing returns. New lines of inquiry, using rich micro‐level data on firms and workers, dynamic general equilibrium models at the macro level, more attention for spatial and temporal variation in the impacts of agglomeration, and further investigations into the spatial scope of externalities are promising avenues for further research that can enhance our understanding of how agglomeration externalities continue to fuel our increasingly urbanized world.     

Raising the Bar (3)

This editorial summarizes and comments on the papers published in issue 11(3) so as to raise the bar in applied spatial economic research and highlight new trends. The first paper proposes spatial and a-spatial indicators to describe the networks of airline companies around the world. The second paper sets forth a two-regime gravity-type model with an endogenous threshold parameter to assess the effect of labour market conditions on interregional migration flows. The third paper utilizes micro-data to explain student migration flows to higher education institutions. The fourth paper is among the first to make use of simulation-based location quotients in a multiregional input–output model. Finally, the last paper provides a purely economic–theoretical model on cooperative limit pricing in the context of spatial competition.     

Network concentration and airport congestion in a post de-regulation context: A case study of Brazil 2000–2010

This paper empirically investigates the main drivers of airline network concentration in an air transport market subject to rapid growth. We consider the Brazilian air transport industry of the 2000s, in which network concentration rapidly increased and was followed by a period of massive flight delays and cancelations, which resulted in the “big blackout” of 2006–2007. We develop an econometric model of network concentration, accounting for demand, cost and competition variables that may affect the propensity of carriers to concentrate flights and passenger connections on a few airports of a network. The main focus of the paper is on the relation between networks leading to the problems of the blackout episode. We investigate the dynamic pattern of the evolution of concentration before and after the abnormal period of operations and find that concentration began to rise at least six quarters before, and persisted at a high level until two quarters after the blackout – and then plunged steeply toward the end of the decade. We believe that our analysis contributes to an improved understanding of the behavior of air transport systems subject to network concentration and congestion. With respect to methodology, we suggest and employ the use of alternative measures of network concentration to check the robustness and validity of our results.     

Interregional trade network analysis for road freight transport in Greece

This paper suggests a flexible decision support framework for the strategic planning of a freight transport hub network in Greece. The proposed methodology treats practical aspects related to the optimal number, location and geographical covering of hubs, through the network analysis of interregional trade, based on original survey data for road freight flows during 2004–2012. The results offer insights into the hierarchical structure of the network and related investment priorities, as the hub role of a prefecture is found to be strongly influenced by high population densities and manufacturing specialization, and its location along highway corridors.