  We use bank-level balance sheet data from 2005 to 2010 to study interactions
within the banking system of five emerging countries: Argentina, Brazil,
Mexico, South Africa, and Taiwan. For each country we construct a financial
network based on the leverage ratio dependence between each pair of banks, and
find results that are comparable across countries. Banks present a variety of
leverage ratio behaviors. This leverage diversity produces financial networks
that exhibit a modular structure characterized by one large bank community,
some small ones and isolated banks. There exist compact structures that have
synchronized dynamics. Many groups of banks merge together creating a financial
network topology that converges to a unique big cluster at a relatively low
leverage dependence level. Finally, we propose a model that includes corporate
and interbank loans for studying the banking system. This model generates
networks similar to the empirical ones. Moreover, we find that faster-growing
banks tend to be more highly interconnected between them, and this is also
observed in empirical data.
