01641nas a2200217   4500000000100000008004100001653002300042653001700065653001400082653002500096653001800121100002800139700001500167700002000182245004900202856005300251300001100304490000800315520108600323022001401409       2020                            d10acommunity networks10aCost sharing10aEconomics10aInternet access cost10aShapley value1 aLlorenç Cerdà-Alabern1 aRoger Baig1 aLeandro Navarro00aOn the Guifi.net community network economics  u/sites/default/files/dsg/Guifi_net_Economics.pdf  a1070670 v1683 aHow costs are distributed among the participants is a key question in the management and viability of shared resources. Although all cost-sharing mechanisms are subjective and thus it is eventually up to the participants to accept one or another, some general criteria seem desirable, such as being budget-balanced and that, in any case, a participant pays more when not cooperating with anyone else. In this paper, we analyse the cost-sharing mechanism that the Guifi.net community network has developed and put in practice to split the transit costs among their more than 20 participants for almost a decade. Our results show that the Guifi.net’s cost-sharing mechanism of the external connectivity, which comprises an equal membership fee for each participant plus a proportional distribution of the remaining costs according to the resource consumption, yields a cost assignment similar to the Shapley value. Our analysis also shows that any alternative to the coalition of all participants entails significant total cost increases and detrimental widespread cost allocation.  a1389-1286