The properties of the interbank market have been discussed widely in the literature . However a proper model selection between URLanizations of the network in a small number of blocks, for example bipartite, core-periphery, and modular , has not been performed. In this paper, by inferring a Stochastic Block Model on the e-MID interbank market in the period 2010-2014 , we show that in normal conditions the network URLanized either as a bipartite structure or as a three community structure, where a group of intermediaries mediates between borrowers and lenders . In exceptional conditions, such as after LTRO, one of the most important unconventional measure by ECB at the beginning of 2012, the most likely structure becomes a random one and only in 2014 the e-MID market went back to a normal URLanization. By investigating the strategy of individual banks,  we show that the disappearance of many lending banks and the strategy switch of a very small set of banks from borrower to lender is likely at the origin of this structural change.
The topological properties of interbank networks have been discussed widely in the literature mainly because of their relevance for systemic risk. Here we propose to use the Stochastic Block Model to investigate and perform a model selection among several possible two URLanizations of the network : these include bipartite, core-periphery, and modular structures. We apply our method to the e-MID interbank market in the period 2010-2014 and we show that in normal conditions the most likely URLanization is a bipartite structure . In exceptional conditions, such as after LTRO, one of the most important unconventional measures by ECB at the beginning of 2012, the most likely structure becomes a random one and only in 2014 the e-MID market went back to a normal URLanization. By investigating the strategy of individual banks, we explore possible explanations and we show that the disappearance of many lending banks and the strategy switch of a very small set of banks from borrower to lender is likely at the origin of this structural change.
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properties of the interbank market
topological properties of interbank networks
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. However a proper model selection between
mainly because of their relevance for systemic risk. Here we propose to use the Stochastic Block Model to investigate and perform a model selection among several possible two
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in a small number of blocks, for example
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structures. We apply our method to
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network URLanized either as
most likely URLanization is
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or as a three community structure, where a group of intermediaries mediates between borrowers and lenders
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measure
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we explore possible explanations and