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on Network Economics |
| By: | Sjaak Hurkens; Doh-Shin Jeon |
| Abstract: | In this paper, we study how access pricing affects network competition when subscription demand is elastic and each network uses non-linear prices and can apply termination-based price discrimination. In the case of a fixed per minute termination charge, we find that a reduction of the termination charge below cost has two opposing effects: it softens competition but helps to internalize network externalities. The former reduces mobile penetration while the latter boosts it. We find that firms always prefer termination charge below cost for either motive while the regulator prefers termination below cost only when this boosts penetration. Next, we consider the retail benchmarking approach (Jeon and Hurkens, 2008) that determines termination charges as a function of retail prices and show that this approach allows the regulator to increase penetration without distorting call volumes. |
| Keywords: | Mobile Penetration, Termination Charge, Access Pricing, Networks, Interconnection, Regulation, Telecommunications. |
| JEL: | D4 K23 L51 L96 |
| Date: | 2009–07–31 |
| URL: | http://d.repec.org/n?u=RePEc:aub:autbar:777.09&r=net |
| By: | Matteo Barigozzi; Giorgio Fagiolo; Diego Garlaschelli |
| Abstract: | We study the topological properties of the multi-network of commodity-specific trade relations among world countries over the 1992-2003 period, comparing them with those of the aggregate-trade network, known in the literature as the international trade network (ITN). We show that link-weight distributions of commodity-specific networks are extremely heterogeneous and (quasi) log-normality of aggregate link-weight distribution is generated as a sheer outcome of aggregation. Commodity-specific networks also display average connectivity, clustering and centrality levels very different from their aggregate counterpart. We also find that ITN complete connectivity is mainly achieved through the presence of many weak links that keep commodity-specific networks together, and that the correlation structure existing between topological statistics within each single network is fairly robust and mimics that of the aggregate network. Finally, we employ cross-commodity correlations between link weights to build taxonomies of commodities. Our results suggest that on the top of a relatively time-invariant ''intrinsic'' taxonomy (based on inherent between-commodity similarities), the roles played by different commodities in the ITN have become more and more dissimilar, possibly as the result of an increased trade specialization. |
| Keywords: | Weighted directed networks; International trade network; Multi-networks; Commodity-specific trade; Econophysics |
| JEL: | F10 D85 |
| Date: | 2009–08–31 |
| URL: | http://d.repec.org/n?u=RePEc:ssa:lemwps:2009/09&r=net |
| By: | Giorgio Fagiolo |
| Abstract: | This paper begins to explore the determinants of the topological properties of the international - trade network (ITN). We fit bilateral-trade flows using a standard gravity equation to build a ''residual'' ITN where trade-link weights are depurated from geographical distance, size, border effects, trade agreements, and so on. We then compare the topological properties of the original and residual ITNs. We find that the residual ITN displays, unlike the original one, marked signatures of a complex system, and is characterized by a very different topological architecture. Whereas the original ITN is geographically clustered and organized around a few large-sized hubs, the residual ITN displays many small-sized but trade-oriented countries that, independently of their geographical position, either play the role of local hubs or attract large and rich countries in relatively complex trade-interaction patterns. |
| Keywords: | International Trade Network; Gravity Equation; Weighted Network Analysis; Topological Properties; Econophysics |
| JEL: | F10 D85 |
| Date: | 2009–08–31 |
| URL: | http://d.repec.org/n?u=RePEc:ssa:lemwps:2009/08&r=net |