MEASUREMENT THE CONCENTRATION OF CONTROL IN OWNERSHIP STRUCTURE OF REAL JOINT-STOCK COMMERCIAL BANKS IN VIETNAM: A CASE STUDY OF SACOMBANK

Bank governance has become an important policy question after the 2008 financial crisis. Many previous studies showed that the impact of bank regulations on bank risks is depended on each bank's ownership structure. Banks with more powerful owners tend take greater risks. The measurement and evaluation the ownership concentration in the structure of the real joint-stock commercial banks will provide useful information for the government in making policies and restructuring the banking system. There are two major issues to analyze the ownership structure and the controlling power of the ultimate ownerships in the real joint-stock commercial banks: the lack of sufficient information and the excessive complexity of the ownership structures. This paper introduces an approach method to estimate the controlling power of the ultimate ownerships in joint-stock commercial banks in Vietnam based on calculating and updating the Banzhaf Index with the best available information in a real joint-stock commercial bank. A case study of Saigon Thuong Tin Joint Stock Commercial Bank (Sacombank) also points out the high level concentration of control in the ownership structure in a real joint-stock commercial bank in Vietnam. Only a coalition of a family group and another bank is able to take over and control Sacombank. Above proposed method could be applied to many other similar cases.