Way of Banking Development Abroad: Branches or Subsidiaries

The purpose of the study is to show what kind of risks would have emerged for bank depositors if there are economical and political risks in a given country. For example, as is the case with the crisis in Greece, a threat or salvation for the banking organizational forms abroad exists regarding which type of bank development is more efficient, branches or subsidiaries. Respectively why do the big banks prefer to operate through branches and those which are focused on retail sales through subsidiaries? What impact could the political and economic risks have on the required reserves on the parent bank? Does the decision depend on the applied organizational form of the bank or on other reasons?