title: Preferential attachment in multiple trade networks.
abstract: In this paper we develop a model for the evolution of multiple networks which is able to replicate the concentrated and sparse nature of world trade data. Our model is an extension of the preferential attachment growth model to the case of multiple networks. Countries trade a variety of goods of different complexity. Every country progressively evolves from trading less sophisticated to high-tech goods. The probabilities of capturing more trade opportunities at a given level of complexity and of starting to trade more complex goods are both proportional to the number of existing trade links. We provide a set of theoretical predictions and simulative results. A calibration exercise shows that our model replicates the same concentration level of world trade as well as the sparsity pattern of the trade matrix. We also discuss a set of numerical solutions to deal with large multiple networks.
authors.affiliation: LIME, IMT School for Advanced Studies, Lucca, Italy.
authors.forename: Rachele
authors.initials: R
authors.lastname: Foschi
authors.affiliation: LIME, IMT Schoool for Advanced Studies, Lucca, Italy and DMSI, K.U. Leuven, Leuven, Belgium.
authors.forename: Massimo
authors.initials: M
authors.lastname: Riccaboni
authors.affiliation: School of International Studies and Department of Economics and Management, University of Trento, Trento, Italy and OFCE-DRIC, France.
authors.forename: Stefano
authors.initials: S
authors.lastname: Schiavo
mesh_terms: D002138:Calibration; D003132:Commerce; D003198:Computer Simulation; D038622:Internationality; D008962:Models, Theoretical