The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Richard E Baldwin - One of the best experts on this subject based on the ideXlab platform.
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the core Periphery model with forward looking expectations
Regional Science and Urban Economics, 2001Co-Authors: Richard E BaldwinAbstract:Abstract Much of the ‘economic geography’ literature assumes myopic migrants, so a key question is whether the results derived hold when migrants think about the future. The question is addressed by introducing a set of techniques – partly analytic and partly numerical – that allow consideration of forward-looking expectations in the standard core-Periphery model. The techniques reveal a startling result. Forward-looking behaviour is shown analytically to never affect the ‘break’ and ‘sustain’ points. Simulation of global adjustment paths shows that forward-looking expectations have no qualitative effect on the model’s behaviour when migration costs are high; here myopia is truly an assumption of convenience. If migration costs are lower, history-versus-expectations considerations emerge and agglomeration can be a self-fulfilling prophecy.
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the core Periphery model with forward looking expectations
Social Science Research Network, 1999Co-Authors: Richard E BaldwinAbstract:The "core-Periphery model" is vitiated by its assumption of static expectations. That is, migration (inter-regional or intersectoral) is the key to agglomeration, but migrants base their decision on current wage differences alone--even though migration predictably alters wages and workers are (implicitly) infinitely lived. The assumption was necessary for analytic tractability. The model can have multiple stable equilibria, so allowing forward-looking expectations would have forced consideration of the very difficult--perhaps even intractable--issues of global stability in non-linear dynamic systems. This paper's main contribution is to present a set of solution techniques--partly analytic and partly numerical--that allow us to consider forward-looking expectations. These techniques reveal a startling result. If quadratic migration costs are sufficiently high, allowing forward-looking behavior has no impact on the main results, so static expectations are truly an assumption of convenience. If migration costs are lower, however, forward-looking behavior creates history-vs-expectations considerations. In this case, agglomeration can be a self-fulfilling prophecy.
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the core Periphery model with forward looking expectations
Research Papers in Economics, 1999Co-Authors: Richard E BaldwinAbstract:The 'core-Periphery model' is vitiated by its assumption of static expectations. That is, migration (inter-regional or intersectoral) is the key to agglomeration, but migrants base their decision on current wage differences alone--even though migration predictably alters wages and workers are (implicitly) infinitely lived. The assumption was necessary for tractability. The model has multiple stable equilibria, so forward-looking behaviour requires characterisation of global stability in a non-linear dynamic system (a potentially intractable problem). This paper's main contribution is to present a set of solution techniques-partly analytic and partly numerical-that allows consideration of forward-looking expectations. Surprisingly, we find that if migration costs are sufficiently high, allowing forward-looking behaviour changes nothing, so static expectations are truly an assumption of convenience. If migration costs are lower, history-vs-expectations considerations emerge. Agglomeration, therefore, can be a self-fulfilling prophecy.
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the core Periphery model and endogenous growth
1997Co-Authors: Rikard Forslid, Richard E BaldwinAbstract:This paper presents a model in which long-run growth and industrial location are jointly endogenous. Specifically, it introduces Romer-Grossman-Helpman endogenous growth into Krugman’s core-Periphery model with footloose labour. The paper focuses on stability of the symmetric equilibrium, showing that growth is a powerful destabilising force. For instance, even with prohibitive trade barriers, the symmetric equilibrium is unstable as long as workers’ discount rates are not too high. It also shows that inter-regional learning spillovers are a stabilizing force. Finally, the paper shows that agglomeration of industry is favourable to growth in both regions, so positive growth effects might offset the well-known static welfare loss that the Periphery experiences when the core-Periphery outcome occurs.
Brian Uzzi - One of the best experts on this subject based on the ideXlab platform.
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structure and dynamics of core Periphery networks
Journal of Complex Networks, 2013Co-Authors: Peter Csermely, Andras London, Lingyun Wu, Brian UzziAbstract:Recent studies uncovered important core/Periphery network structures characterizing complex sets of cooperative and competitive interactions between network nodes, be they proteins, cells, species or humans. Better characterization of the structure, dynamics and function of core/Periphery networks is a key step of our understanding cellular functions, species adaptation, social and market changes. Here we summarize the current knowledge of the structure and dynamics of "traditional" core/Periphery networks, rich-clubs, nested, bow-tie and onion networks. Comparing core/Periphery structures with network modules, we discriminate between global and local cores. The core/Periphery network organization lies in the middle of several extreme properties, such as random/condensed structures, clique/star configurations, network symmetry/asymmetry, network assortativity/disassortativity, as well as network hierarchy/anti-hierarchy. These properties of high complexity together with the large degeneracy of core pathways ensuring cooperation and providing multiple options of network flow re-channelling greatly contribute to the high robustness of complex systems. Core processes enable a coordinated response to various stimuli, decrease noise, and evolve slowly. The integrative function of network cores is an important step in the development of a large variety of complex organisms and organizations. In addition to these important features and several decades of research interest, studies on core/Periphery networks still have a number of unexplored areas.
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structure and dynamics of core Periphery networks
Journal of Complex Networks, 2013Co-Authors: Peter Csermely, Andras London, Brian UzziAbstract:Recent studies uncovered important core/Periphery network structures characterizing complex sets of cooperative and competitive interactions between network nodes, be they proteins, cells, species or humans. Better characterization of the structure, dynamics and function of core/Periphery networks is the key step to our understanding of cellular functions, species adaptation, social and market changes. Here we summarize the current knowledge of the structure and dynamics of ‘traditional’ core/Periphery networks, rich-clubs, nested, bow-tie and onion networks. By comparing core/Periphery structures with network modules, we discriminate between global and local cores. The core/Periphery network organization lies in the middle of several extreme properties, such as random/condensed structures, clique/star configurations, network symmetry/asymmetry, network assortativity/disassortativity, as well as network hierarchy/anti-hierarchy. These properties of high complexity together with the large degeneracy of core pathways ensuring cooperation and providing multiple options of network flow re-channelling greatly contribute to the high robustness of complex systems. Core processes enable a coordinated response to various stimuli, decrease noise and evolve slowly. The integrative function of network cores is an important step in the development of a large variety of complex organisms and organizations. In addition to these important features and several decades of research interest, studies on core/Periphery networks still have a number of unexplored areas.
Jason H Brickner - One of the best experts on this subject based on the ideXlab platform.
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dna zip codes control an ancient mechanism for gene targeting to the nuclear Periphery
Nature Cell Biology, 2010Co-Authors: Sara Ahmed, Donna Garvey Brickner, Ivelisse Cajigas, William H Light, Michele Mcdonough, Alexander B Froyshteter, Tom Volpe, Jason H BricknerAbstract:In budding yeast, many inducible genes translocate to the nuclear Periphery when activated. Sequence motifs have now been identified in promoters, which target genes to the nuclear Periphery and contribute to gene activation
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h2a z mediated localization of genes at the nuclear Periphery confers epigenetic memory of previous transcriptional state
PLOS Biology, 2007Co-Authors: Donna Garvey Brickner, Ivelisse Cajigas, Yvonne N Fondufemittendorf, Sara Ahmed, Peichih Lee, Jonathan Widom, Jason H BricknerAbstract:Many genes are recruited to the nuclear Periphery upon transcriptional activation. The mechanism and functional significance of this recruitment is unclear. We find that recruitment of the yeast INO1 and GAL1 genes to the nuclear Periphery is rapid and independent of transcription. Surprisingly, these genes remain at the Periphery for generations after they are repressed. Localization at the nuclear Periphery serves as a form of memory of recent transcriptional activation, promoting reactivation. Previously expressed GAL1 at the nuclear Periphery is activated much more rapidly than long-term repressed GAL1 in the nucleoplasm, even after six generations of repression. Localization of INO1 at the nuclear Periphery is necessary and sufficient to promote more rapid activation. This form of transcriptional memory is chromatin based; the histone variant H2A.Z is incorporated into nucleosomes within the recently repressed INO1 promoter and is specifically required for rapid reactivation of both INO1 and GAL1. Furthermore, H2A.Z is required to retain INO1 at the nuclear Periphery after repression. Therefore, H2A.Z-mediated localization of recently repressed genes at the nuclear Periphery represents an epigenetic state that confers memory of transcriptional activation and promotes reactivation.
Peter Csermely - One of the best experts on this subject based on the ideXlab platform.
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structure and dynamics of core Periphery networks
Journal of Complex Networks, 2013Co-Authors: Peter Csermely, Andras London, Lingyun Wu, Brian UzziAbstract:Recent studies uncovered important core/Periphery network structures characterizing complex sets of cooperative and competitive interactions between network nodes, be they proteins, cells, species or humans. Better characterization of the structure, dynamics and function of core/Periphery networks is a key step of our understanding cellular functions, species adaptation, social and market changes. Here we summarize the current knowledge of the structure and dynamics of "traditional" core/Periphery networks, rich-clubs, nested, bow-tie and onion networks. Comparing core/Periphery structures with network modules, we discriminate between global and local cores. The core/Periphery network organization lies in the middle of several extreme properties, such as random/condensed structures, clique/star configurations, network symmetry/asymmetry, network assortativity/disassortativity, as well as network hierarchy/anti-hierarchy. These properties of high complexity together with the large degeneracy of core pathways ensuring cooperation and providing multiple options of network flow re-channelling greatly contribute to the high robustness of complex systems. Core processes enable a coordinated response to various stimuli, decrease noise, and evolve slowly. The integrative function of network cores is an important step in the development of a large variety of complex organisms and organizations. In addition to these important features and several decades of research interest, studies on core/Periphery networks still have a number of unexplored areas.
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structure and dynamics of core Periphery networks
Journal of Complex Networks, 2013Co-Authors: Peter Csermely, Andras London, Brian UzziAbstract:Recent studies uncovered important core/Periphery network structures characterizing complex sets of cooperative and competitive interactions between network nodes, be they proteins, cells, species or humans. Better characterization of the structure, dynamics and function of core/Periphery networks is the key step to our understanding of cellular functions, species adaptation, social and market changes. Here we summarize the current knowledge of the structure and dynamics of ‘traditional’ core/Periphery networks, rich-clubs, nested, bow-tie and onion networks. By comparing core/Periphery structures with network modules, we discriminate between global and local cores. The core/Periphery network organization lies in the middle of several extreme properties, such as random/condensed structures, clique/star configurations, network symmetry/asymmetry, network assortativity/disassortativity, as well as network hierarchy/anti-hierarchy. These properties of high complexity together with the large degeneracy of core pathways ensuring cooperation and providing multiple options of network flow re-channelling greatly contribute to the high robustness of complex systems. Core processes enable a coordinated response to various stimuli, decrease noise and evolve slowly. The integrative function of network cores is an important step in the development of a large variety of complex organisms and organizations. In addition to these important features and several decades of research interest, studies on core/Periphery networks still have a number of unexplored areas.
Peter J Mucha - One of the best experts on this subject based on the ideXlab platform.
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core Periphery structure in networks revisited
Siam Review, 2017Co-Authors: Puck M Rombach, Mason A Porter, James H Fowler, Peter J MuchaAbstract:Intermediate-scale (or “meso-scale'') structures in networks have received considerable attention, as the algorithmic detection of such structures makes it possible to discover network features that are not apparent either at the local scale of nodes and edges or at the global scale of summary statistics. Numerous types of meso-scale structures can occur in networks, but investigations of such features have focused predominantly on the identification and study of community structure. In this paper, we develop a new method to investigate the meso-scale feature known as core-Periphery structure, which entails identifying densely connected core nodes and sparsely connected peripheral nodes. In contrast to communities, the nodes in a core are also reasonably well-connected to those in a network's Periphery. Our new method of computing core-Periphery structure can identify multiple cores in a network and takes into account different possible core structures. We illustrate the differences between our method and...
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core Periphery structure in networks
Siam Journal on Applied Mathematics, 2014Co-Authors: Puck M Rombach, Mason A Porter, James H Fowler, Peter J MuchaAbstract:Intermediate-scale (or “meso-scale'') structures in networks have received considerable attention, as the algorithmic detection of such structures makes it possible to discover network features that are not apparent either at the local scale of nodes and edges or at the global scale of summary statistics. Numerous types of meso-scale structures can occur in networks, but investigations of such features have focused predominantly on the identification and study of community structure. In this paper, we develop a new method to investigate the meso-scale feature known as core-Periphery structure, which entails identifying densely connected core nodes and sparsely connected peripheral nodes. In contrast to communities, the nodes in a core are also reasonably well connected to those in a network's Periphery. Our new method of computing core-Periphery structure can identify multiple cores in a network and takes into account different possible core structures. We illustrate the differences between our method and...
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core Periphery structure in networks
arXiv: Social and Information Networks, 2012Co-Authors: Puck M Rombach, Mason A Porter, James H Fowler, Peter J MuchaAbstract:Intermediate-scale (or `meso-scale') structures in networks have received considerable attention, as the algorithmic detection of such structures makes it possible to discover network features that are not apparent either at the local scale of nodes and edges or at the global scale of summary statistics. Numerous types of meso-scale structures can occur in networks, but investigations of such features have focused predominantly on the identification and study of community structure. In this paper, we develop a new method to investigate the meso-scale feature known as core-Periphery structure, which entails identifying densely-connected core nodes and sparsely-connected Periphery nodes. In contrast to communities, the nodes in a core are also reasonably well-connected to those in the Periphery. Our new method of computing core-Periphery structure can identify multiple cores in a network and takes different possible cores into account. We illustrate the differences between our method and several existing methods for identifying which nodes belong to a core, and we use our technique to examine core-Periphery structure in examples of friendship, collaboration, transportation, and voting networks.
