Greedy algorithms and Zipf laws

We consider a simple model of firm/city/etc growth based on a multi-item criterion: whenever entity B fares better than entity A on a subset of M items out of K, the agent originally in A moves to B. We solve the model analytically in the cases K  =  1 and . The resulting stationary distribution of...

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Main Authors: Moran, J, Bouchaud, J-P
Format: Journal article
Language:English
Published: IOP Publishing 2018
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author Moran, J
Bouchaud, J-P
author_facet Moran, J
Bouchaud, J-P
author_sort Moran, J
collection OXFORD
description We consider a simple model of firm/city/etc growth based on a multi-item criterion: whenever entity B fares better than entity A on a subset of M items out of K, the agent originally in A moves to B. We solve the model analytically in the cases K  =  1 and . The resulting stationary distribution of sizes is generically a Zipf-law provided M  >  K/2. When , no selection occurs and the size distribution remains thin-tailed. In the special case M  =  K, one needs to regularize the problem by introducing a small 'default' probability phgr. We find that the stationary distribution has a power-law tail that becomes a Zipf-law when . The approach to the stationary state can also be characterized, with strong similarities with a simple 'aging' model considered by Barrat and Mézard.
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spelling oxford-uuid:9a2c7f8f-cfee-4d0f-a1e1-1dbb7d4a0fd12022-03-27T00:19:36ZGreedy algorithms and Zipf lawsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:9a2c7f8f-cfee-4d0f-a1e1-1dbb7d4a0fd1EnglishSymplectic ElementsIOP Publishing2018Moran, JBouchaud, J-PWe consider a simple model of firm/city/etc growth based on a multi-item criterion: whenever entity B fares better than entity A on a subset of M items out of K, the agent originally in A moves to B. We solve the model analytically in the cases K  =  1 and . The resulting stationary distribution of sizes is generically a Zipf-law provided M  >  K/2. When , no selection occurs and the size distribution remains thin-tailed. In the special case M  =  K, one needs to regularize the problem by introducing a small 'default' probability phgr. We find that the stationary distribution has a power-law tail that becomes a Zipf-law when . The approach to the stationary state can also be characterized, with strong similarities with a simple 'aging' model considered by Barrat and Mézard.
spellingShingle Moran, J
Bouchaud, J-P
Greedy algorithms and Zipf laws
title Greedy algorithms and Zipf laws
title_full Greedy algorithms and Zipf laws
title_fullStr Greedy algorithms and Zipf laws
title_full_unstemmed Greedy algorithms and Zipf laws
title_short Greedy algorithms and Zipf laws
title_sort greedy algorithms and zipf laws
work_keys_str_mv AT moranj greedyalgorithmsandzipflaws
AT bouchaudjp greedyalgorithmsandzipflaws