title: Widespread occurrence of the inverse square distribution in social sciences and taxonomy.
abstract: The widespread occurrence of an inverse square relation in the hierarchical distribution of subcommunities within communities (or subspecies within species) has been recently invoked as a signature of hierarchical self-organization within social and ecological systems. Here we show that, whether such systems are self-organized or not, this behavior is the consequence of the treelike classification method. Different treelike classifications (both of real and truly random systems) display a similar statistical behavior when considering the sizes of their sub-branches.
authors.affiliation: INFM, UdR ROMA 1, Dipartimento di Fisica, Università di Roma La Sapienza, Piazzale Aldo Moro 2, 00185 Rome, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Caldarelli
authors.forename: Cécile
authors.initials: C
authors.lastname: Caretta Cartozo
authors.forename: Paolo
authors.initials: P
authors.lastname: De los Rios
authors.forename: Vito D P
authors.initials: VD
authors.lastname: Servedio