B O I H C KINH T TP.H NG D Y KINH T FULBRIGHT KAM KIM LONG NG C A C N K T QU HO IC NG KINH DOANH C PH M IC PH N S LU CH NH S CH C NG TP H N H U B O I H C KINH T TP.H NG D Y KINH T FULBRIGHT KAM KIM LONG NG C A C U N K T QU HO IC NG KINH DOANH C PH M IC PH : 60340402 LU CH NH S CH C NG NG D N KHOA H C: GS.TS DAVID O DAPICE TP H N H U -i- L c hi s d ng lu c d n ngu hi u bi t c h c Kinh t t ph m vi t thi t ph H li u mc i ng d y kinh t Fulbright H Kam Kim Long -ii- L IC Lu ng k tr l ng th nd n th ch c i n, um ic il ic u n Th i th ng th c ti ng k ng d t c th c hi n lu c m t ph n lu c t il ic n Th Qu tr nh nh th il ic n Th c u nh ng thu i chi u t i nhi u tu n li n n Th y Nguy b n ng bu i Seminar m c th ic at n lu Kam Kim Long -iii- T LU C i c ph n hi n s n kinh t c c c t quan tr i gian qua, nhi u tr c tr c v hi n tr ng h v c ti m n r i ro cho h th ng n ki u a vi l s h u tr c ti p c i ng quy n ki N cc u tr ng i v s h u th c t nh Lu h u ng tr c ti p quy n l c ki , thay s h c qu n tr t Hi n nay, c ch m ph c t o nh ng b t Trong m c n c n th c iv i u th ng tin v c i thi u m s d ng tr c ti p quy n l c ki m i c ph n Vi t Nam b ng c a ch s quy n l c Banzhaf ng th c gi i quy ng phi u, ng ch s th c t y y c c s ki ,m trung c a quy n ki cho vi c ng c a c h nr u qu ho m i c ph n M ti t p nh ng c t qu thu t ng c a ng ti ng c a m c ac lu y quy n-th , h d ng t qu th u qu ho t d u th c nghi m c chung, m h uc am c th c hi n t p trung cao c i m hi u qu ho ng s ki h thu c, s h ra, tv ng c lo i ch s h u h ng m nh b i y u t th ch c c i c ch t c Scandinavie m t p -ivtrung c h u i ro ho ng hi u qu ng ng Sacombank b , ng , cho th y s c c a cu , lu s d ng ngu n s li t qu m t s hi n p ph n bi n t ng T v n t p trung cao c a quy n ki m tm c h u Ch m t m g m chi ph Hi n nay, Sacombank v nh v lo i c c Vi t Nam T th y c h u hi n h ho n, ti i ro ho Hi n n hi u qu ng acombank n tr ng c u hi u cho th th ng NHTMCP ng hi n ch t i th ng ti i ro c n Sacombank c Vi th c s c ho p ph c t p Trong n c u hi u qu h chi ph i b i m ch v lu ah n hi u qu u ti t c a NHNN r c hi u qu -v- M CL C L i L IC ii T LU iii M C L C v DANH M , B NG BI U vii GI I THI U T 1.1 B ic 1.2 U u T 1.2.1 T uv 1.2.2 T ng c 1.3 ng quy n ki i uv ng c a c h t qu ho t M u 1.3.1 M i u 1.4 u 1.5 u NG QUY N KI 2.1 ng quy n ki 2.2 ng quy n l c ki ac s ng ch s Banzhaf h u tr c ti p cs h s Banzhaf thi NG C A C NG C 3.1 qua vi p v c ng c HO P ng c a c quy n ki s Banzhaf v c h u 13 H NR U QU 15 h t qu ho ng kinh doanh c 15 3.1.1 M n y quy n - th 3.1.2 V y quy n-th i 16 3.1.3 V y quy n-th i 16 3.2 doanh c h uc a 15 uv ng c a c h t qu ho ng kinh 17 3.3 T ng k ng c a c u tr h t qu ho ng c a m t NHTMCP 19 U NG SACOMBANK B 22 -vi4.1 ng Sacombank b 22 4.2 K t qu n l c chi ph i c ng ch s Banzhaf 22 c th 4.2.2 T i th 4.3 4.4 m Sacombank b m Sacombank b 24 ng c a c h uc t qu ho ng c a 26 Nh m ch ng l K T LU 5.1 22 t lu N NGH iv ng Sacombank 30 31 n ngh 31 n ngh nh nv n ngh cho gi 5.4 Sacombank 28 30 5.2 5.3 ki n di n H n ch c ng Sacombank 31 n 32 32 LI U THAM KH O 33 PH L C 37 -vii- DANH M , B NG BI U DANH M C B NG BI U 3- ng c a m qu ho t p trung cao c ng c 3-2 h u 18 ng c a s h u qu ho ng c Kenya 18 4- ic h u tr c ti p c a Sacombank c b 22 4- m iv s h 4- 23 u quy n bi u quy t, 2011 23 4- ic h u tr c ti p c a Sacombank, 2012 24 4- s h 25 4-6 S h u c i Sacombank, 2012 25 4- i v s h u n danh, 2012 26 4- i th 4- ih ic a Sacombank 26 ng c n k t qu ho c b 4-10 ng c a 27 ng c Sacombank sau b n k t qu ho ng c a 27 DANH M C H NH V n c a h th Vi n 31/03/2014 ho m t c h a ba doanh nghi p 10 m tc h a b n doanh nghi p 11 ng c a c h n ki t qu ho 15 ng c a c h t qu ho ng c a th ch ki ng kinh doanh c a NHTMCP ng c a NHTMCP 19 ng c ic m quy n 20 n gi a quy n s h u tr c ti n ki 21 -38- X 60% Y 60% 40% A 100 B 30% 30% C D 40% Y.Crama & Leruth (2013) ng h c ti p n m gi c ph n c t nh ng d V m t s h u, X s h nc ac p (60% * 30%) + (60% * 30%) = 36% C, Y s h u (40% * 30%) + (100% * 40%) = 52% C Khi ti phi tham gia bi u quy t t i C Gi s t t c ng h h n chi ph i it ng bi u quy t h u tr c ti p m gi (30%+30%=) 60% quy n bi u quy t t i C Y m h u 40% t i quy n chi ph i c a X, n m gi 40% quy n bi u quy t t i C K t qu m gi t l c ph (D n l ng h p h u tr c ti c a: Y.Crama & Leruth, POWER INDICES AND THE MEASUREMENT OF CONTROL IN CORPORATE STRUCTURES, 2013, P3-4) Ph l c 3: ul i c ph a Vi t Nam ul n tr c a TCTD u l i h th ng qu n tr C ng c t i m i h th ng qu n tr chu n m c qu c -39- m iv b TD - t c phi i c ph - ng ch i c ph ul - ,t i ho ch h md - H n ch s chi ph quy t x ac iv iv i c ph gl c ph n t nh v gi i h n s h u i c ph ch ng vi ph cx nh v nh c a t ch n C n, mua, s h u v n, c ph n ph i ng h p t ch u l i theo ch ih h uv nh s ng mua l i c phi u, v n nh c c Vi t Nam d cx i h n ch m nh nv n t th c c qu n tr , kinh nghi hi n - u ki iv o, qu ch t c t ch h i ng qu n tr /h ng qu n tr /h - ng k ho ch, chi c kinh doanh m i - Tri ib c qu n tr nh c pv u qu cao , chu n m c qu c t t - th ng qu n tr r pv c, chu n m c c a th ng qu n tr r i ro kho n, r th t, t d ng n i b ; th c hi m r r d ng c a TCTD i ro th in pd y ban ng, r i ro th ng x p h pv qu c t -40- im - u qu h th ng ki u, s p x p l ib ph n ch n tr h qu th p x p, b c ngh nghi p t t - Hi th ngh n h th th ib ,h t ib c th ph pv ph c t p ho u qu n tr , a TCTD ph c h i ho c h i, ch n ch nh s th ho c mua l p b t bu nh c c gi i t iv , t ng s h u ch m th c hi n u l i, k c gi i th , thu h i gi c Vi t Nam ch p thu n iv c thu m i ph thi ul b , bao g m c gi i th ms u qu c U L I H TH nh s Ph l c 4: Nh t c CH - cs h NG N 2011- 2015 (Ban a Th gi p (khi c n )) p ph bi n -41- Ngu n: Shinksuke Yakura & Li Guo (2010) -42Ph l c 5: ICFE 2014 - The International Conference on Finance and Economics MEASUREMENT THE CONCENTRATION OF CONTROL IN OWNERSHIP STRUCTURE OF REAL JOINT-STOCK COMMERCIAL BANKS IN VIETNAM: A CASE STUDY OF SACOMBANK Long Kam-Kim, Tuan Do-Thien-Anh, and David O Dapice Abstract 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 ful 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 jointstock 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 Keywords: Banking governance, ownership and control, Banzhaf power index, real jointstock commercial bank, concentration of control, incomplete and indirect ownership structures, Sacombank, Vietnam JEL Classification: G32, G34, G38 INTRODUCTION -43Ownership and control of a bank are two concepts that need to be carefully distinguished Ownership refers to the property of shares and determines the distribution of cash-flow rights Meanwhile, control reflects the ability to influence the strategic decisions of the bank In Bank governance research sector, control right is considered more important than cash-flow right In practice, the controlling power of owner is not easy to measure, due to lack of information and complexity of ownership structures In this paper, for the measurement work, we use the Banzhaf index to measure the level control of shareholders We also examine the impact of different types of indirect ownership to the concentration of control in bank For voting behavior of small and unidentified shareholders, this paper proposed to use the research results of the voting behavior of retail shareholders in banks (Wang, 2009; Yves Crama & Luc Leruth, 2013) Section below will give an overview of joint-stock commercial banks (JSC-banks) system in Vietnam Section shows how to measure the controlling power of ultimate shareholder, section will analysis case of Sacombank and the last section will give discussion AN OVERVIEW OF JSC- BANKS IN VIETNAM Currently, non-bank financial institutions in Vietnam remain underdeveloped, so that, banks system is really the lifeblood of the whole economy In 2013, the State Bank of Vietnam announced the proportion of the total assets of the JSC-banks in Vietnam compared to total assets of the banking system is 41 % Therefore, business performance and financial health of the JSC-banks have a direct influence on the stability of the national finance system and the sustainable economic growth of Vietnam However, until now, there is no previous research to measure and analyze the control right of the ultimate ownerships and the concentration of control in the ownership structure of JSC-banks in Vietnam Currently, there are some studies and experiments indicate high levels of concentration control in ownership structure negatively impact performance and increase the risk of banks (Chen Lin & Yue Ma, 2013; Kiruri & Olkalou, 2013; Lamy, 2012; Johnson & La Porta, 2000) 2.1 JSC-banks in Vietnam have dispersed ownership structure and high centralized control structure Vietnam Law on Credit Institutions 2010 only allows an individual to own no more than 5% shares of a bank to ensure nobody can individual control the bank However, indirect ownership and family ownership are popular in the JSC banks system in Vietnam The -44phenomenon of controlling and dominating in most of JSC-banks in Vietnam by tycoon families is discussed a lot but without enough strong evidences A practical example, Mr Tram-Be was appointed as Deputy Chair of Sacombank in 2012, but he only owns directly 115,000 Sacombank shares, or 0.01 percent of total capital (Source: Sacombank (2013), The 2012 Annual Report of Sacombank ) The State Bank of Vietnam still have not mentioned about measurement of control right or the concentration of control banks Instead that, only limited on the percentage of ownership However, in recent years, government and the State Bank of Vietnam also seriously looked at the problems of indirect ownership among Vietnamese banks Decision 254 of government in -2015, stated that a very important issue in JSC-banks restructuring is focused on increasing the number of investors and shareholders, and limited the dominant and control of the powerful shareholders of the bank 2.2 Three factors make it difficult to determine and measure the control right of shareholders in Vietnam JSC-banks In practice, three features below make it hard, or even impossible to collect complete information about ownership networks First, because of the very huge number of shareholders in JSC-banks and other listed-companies, it is difficult to statistically and full disclosure of ownership structures Follow to current regulation in Vietnam, only shareholders that own directly more than 5% of the shares of joint stock listed companies must be disclosed information That regulation also created the motivation to develop many kinds of indirect ownership in banking system for personal benefits Second, there are different types of shares (one vote per share, or multiple voting rights) and some shareholders may carry a significant amount of voting rights proxy on behalf of other shareholders Third, the weakness of supervision and transparency make regulatory information is not always included in easily accessible databases Indirect ownership and family ownership mentioned above cover the overall picture of the banking sector in Vietnam, so that who is the ultimate owner, and how much is nonperforming loans of each bank was obscured This can restructure the banking system, which will be able to achieve the right targets MEASURE THE CONTROL RIGHT OF ULTIMATE OWNERS 3.1 Brief literatures review -45Corporate governance considers that control rights are derived from voting rights Shareholders of a firm make decisions by voting in a shareholders' meeting Before the serious studies of control, it is confused that the percentage of shareholding is also the power of control, based on an implicit assumption: "one share-one vote" Basically, the voting right of the shareholders is derived from their ownership However, it is important to note that the voting rights are not necessarily proportional to the cash-flow right in direct ownership structure One of the definitions of a controlling shareholder by LaPorta (1999) relies on the concept of a cutoff point That is the first study that investigates the issue of ultimate control However, it does not really provide a measure of control, but only a notion of controlling entity Crama & Leruth (2013) give a brief review of the use of power indices in the corporate governance literature, pointed out the advantages and disadvantages of methods to measure power indices and summary that the controlling power should be determined better by measuring the power index in the game-theoretic framework First studies of voting games have been introduced by Penrose (1946), Shapley & Shubik (1954), Banzhaf(1965) There are two commonly used indicators to measure the power of control is the Shapley-Shubik power index and PenroseBanzhaf power index (or Banzhaf index) 3.2 Measure the control right of shareholders based on Banzhaf index Most of researchers pick either the Shapley Shubik or the Banzhaf index without further justification Until Leech (2002), the first man, who indicated that the Banzhaf index is more suitable than the Shapley Shubik index in coporate governance sector Other researchers also division more suitable to analyze voting right in ownership structures of firms (Felsenthal & Machover, 2005; Levy, 2011, 2012; Crama & Leruth, 2013) The Banzhaf index is a power index defined by the probability of changing an outcome of a , 1965) 3.3 The impact of indirect ownership on Banzhaf index In fact, indirect ownership does not give rise to cash-flow right, but only to an increase of the voting right The impact of indirect ownership on the relationship between ownership and -46control has been emphasized by many researchers (La Porta, 2000; Edwards & Weichenrieder, 2009; Levy, 2011, 2012; Crama & Leruth, 2013) In this section, we will give a review and lead the study results on examine impact of several common indirect ownership structures to the Banzhaf index Impact of Pyramidal structures on Banzhaf index In case of the pyramid structure, ultimate owners own shares and impose their voting right on target companies through subsidiary companies Pyramidal ownership structure changed completely compared Banzhaf index case directly holding the same percentage of shares More explanation about the distinction between ownership and control was presented in detail by Crama & Leruth (2013); Edwards & Weichenrieder (2009) Basically, called B, X, relationship between B with X and Y as follows: 1, w hile xB * X yB Y 0, 0, w hile xB * X B yB * Y 0, while xB, yB is proportional ownership of X, Y in B In more complex cases, manually calculation will be considered difficult, so we could use computer simulation to calculate large sample Impact of Cross ownership on Banzhaf index In cross-ownership structure, the interaction of shares held mutual, polling sequence in the enterprises will also affect the voting results Cross-ownership is defined simply as A owns B and B also owns A However, beside several common cross-ownership, cross-ownership may also exist as hidden form For instance, an investor or group of investors owns both bank A and bank B Then bank A and bank B is cross-owned (Shinksuke Yakura & Li Guo, 2010) Levy (2011) states that the final voting results will converge to the steady states even if the original vote was chaotic If that does not happen, the vote will fail because could not be adopted or rejected the issue In practice, to avoid vote multiple times, they usually set the threshold to pass the vote is 50% + share or 51% or higher By listing all the possible steady state occurs for a structure, Levy (2012) proposes a method to calculate the matrix of Banzhaf indices based on the set of this steady state Impact of family ownership on Banzhaf index -47Family ownerships usually exist in the form of household relatives, investment trusts, subsidiary companies They are often used to pass regulations on the maximum percentage of ownership, to hide information about the ultimate owners Family ownership makes dual impact on Banzhaf indices For example, two shareholders owning A and C respectively and c % a %, but essentially A is ultimate ownership Thus, c % ownership of A is discovered makes two effects: increased control right for A and reduce voting right of all remaining shareholders Banzhaf of A is therefore increased but not simply as Banzhaf of A + Banzhaf of C The affect of family ownership on Banzhaf index is detail presented by John L Teall (2007) 3.4 Estimate Banzhaf indices in floating and incomplete structures Usually, only a few main shareholders of banks are determined For example in Vietnam, the transparency requirements enacted require that shareholders of listing company owning more than 5% of the shares be explicitly identified However, beside major shareholders, public companies often have large numbers of retail shareholders, individual investors, They hold a very small percentage of shares, so that most of them usually not attend to the shareholders' meeting, not know much about business of the firm Many studies of voting behavior call them "other shareholders" In fact, it's very difficult (or even impossible) to collect complete information about real ownership structures There are two extremes of researchers on this issue First extremes considers the voting rights of small shareholders is not concentrated, effected by Herd mentality, so that we should be deliberately ignored their impact, even though in reality they may have a certain influence on the voting results (Shapiro and Shapley 1978; Dubey and Shapley, 1979; Aminadav, 2011) The remaining extremes trying to build Monte-Carlo simulation model uses the convergence of the random Markov chains to try to figure out the probability of voting results similar to a shareholder wishes These models have been criticized for not taking into account the nonrational behavior, crow effect on voters (Leech, 2003; Levy, 2011, 2012) Recent studies by Wang (2009), Crama & Leruth (2013) state that: In the ownership structure that requires cumulative voting (such as JSC banks), small shareholders are forced to link together to get enough votes and then they elect representatives to attend its share capital shareholders meeting or election to board In these cases, the Banzhaf indices converge to values that only depend on the weights of the major players This assumption will be used to analyze other shareholders of Sacombank -484 A CASE STUDY OF SACOMBANK Sacombank is considered as a typical JSC-bank in Vietnam The State Bank of Vietnam ranked this bank in group A, the group of banks with the highest competitiveness In the end of 2011, the information about a attempt group of shareholders try to collect 51 percent concerns surrounding this event, a lot of information related to the ownership structure of Sacombank, organizations participating acquirer and the indirect ownership structure is also gradually revealed This event gives us the opportunity to access, research and analysis the ownership structure of a real JSC-bank in Vietnam Until that time, Sacombank was believed Before acquisition Table 4.1 below will show information about the major ownerships of Sacombank in the direct ownership structure, such as name, percentage of ownership and corresponding Banzhaf index Follow this direct ownership structure, observed the column of Banzhaf indices, there is no one absolute dominant shareholder in Sacombank, but ANZ is a strongest shareholder in both cash flow right and control right Tab 4.1 Banzhaf index with the direct ownership structure before the acquisition Name of Shareholder Percentage of Ownership Banzhaf Index ANZ Dragon Capital Dang Van Thanh Dang Hong Anh REE 9,61 6,66 3,98 3,92 3,46 44% 20% 12% 12% 12% Source: Sacombank (2011) However, in this structure exists "family ownership" between father-Dang Van Thanh and son-Dang Hong Anh, so that, impart of family ownership to Banzhaf index is showed in Table 4.2 below Now, observed changes in column Banzhaf to consider ANZ, Tha and Dragon Capital in the same level of control right But, there is still no one absolute dominant shareholder in Sacombank Tab 4.2 Banzhaf index with "family ownership" before the acquisition Name of Shareholder ANZ Percentage of Ownership Banzhaf Index 9,61 7,44 33,33% 33,33% -49Dragon Capital REE 6,66 3,92 33,33% 0% Source: calculated form Tab 4.1 Sacombank chairman Dang Van Thanh said in a statement released in the annual meeting of shareholders of Sacombank in 2010, ANZ has plans to sell stake in Sacombank The move comes due to ANZ was finally granted permission to operate as a fully-owned foreign subsidiary by the State Bank of Vietnam in 2008 However, ANZ will implement appropriate route divestments; During that time, Mr Dang Van Thanh was the person authorized by ANZ for 9.61% of bank capital in Sacombank Now, we continue calculate with this updating Tab 4.3 Banzhaf index with voting rights proxy before the acquisition Name of Shareholder Percentage of Ownership Banzhaf Index Dragon Capital REE 17,05% 6,66% 3,92% 100% 0% 0% Source: calculated form Tab 4.2 At the end of 2011, actually, Mr Dang Van Thanh and his family members (his wife, son and daughter), hold high position in Sacombank and other subordinate companies In this step, olutely control Sacombank ANZ is a very important role in the coalition that Thanh to control Sacombank That explains why the ANZ leaves bring failure for Thanh in Sacombank At the time of acquisition Some big shareholders have withdrawn capital from Sacombank, such as Dragon Capital, ANZ bank, REE, while new shareholders have appeared, including Eximbank Table 4.4 below shows the direct ownership structure of Sacombank at the time start of acquisition At that time, Eximbank has replaced ANZ became the largest shareholder of Sacombank and claims to represent more than 51% of the voting rights in Sacombank Tab 4.4 Banzhaf index with the direct ownership structure at time of the acquisition Name of Shareholder Percentage of Ownership Banzhaf Index Eximbank 10,73 25,98% Foreign investors 9,9 21,26% Saigon Exim 5,17 11,81% 11,81% Tran Phat Minh -50Dang Van Thanh 4,39 8,66% Dang Hong Anh Saigon A Chau 3,82 8,66% 11,81% Source: Sacombank (2012, 2013) Follow this direct ownership structure, observed Banzhaf index column, there is no one dominant shareholder However, in this structure exists "family ownership" between fatherDang Van Thanh and son- Dang Hong Anh At the same time, there also exists a Pyramidal structure between Eximbank and two subsidiaries of Eximbank: Saigon Exim & Saigon A Chau So that, Banzhaf index column is updated in Table 4.5 below Tab 4.5 Banzhaf index with family ownership & Pyramidal Structure at the time of acquisition Name of Shareholder Percentage of Ownership Banzhaf Index 20,9 Tran Phat Minh 9,9 18,18% 8,21 Foreign investors 54,55% 18,18% 9,09% Source: calculated form Tab 4.4 overwhelmed by Eximbank group However, no one can absolute manipulate Sacombank alone This is an important mystery of the acquisition event Because Eximbank needs another shareholders group to make a strategic alliance for fully control Sacombank Actually, before the acquisition, Tram Be and his family had bought Sacombank shares without disclose disclosure This information was published after the decision of The State Table 4.6 below Tab 4.6 Name of Shareholder Number of shares Percentage of Ownership Tram Trong Ngan Tram Be Tram Thuyet Kieu 48.000.000 4,93% 115.000 0,01% 3.148.953 0,32% -51Tram Khai Hoa 20.820.000 2,14% Source: The State Securities Commission of Vietnam (2012), Decision No 746 and 748/QD-UBCK After update Table 4.5 with information in Table 4.6, the result is showed in Table 4.7 below Tab 4.7 Name of Shareholder Percentage of Ownership Banzhaf Index 18,5 7,7 9,09% 7,4 9,09% Foreign investors 63,64% 9,09% 6,4 9,09% Source: calculated form Tab 4.5 and Tab 4.6 control Sacombank Tab 4.8 Banzhaf index with proxy voting rights at the time of acquisition Name of Shareholder Percentage of Ownership Banzhaf Index 25,9 7,7 0% Foreign investors 100% 0% 6,4 0% Source: calculated form Tab 4.7 After the acquisition and ownership structure changes, new ownership structure of Sacombank no change in the concentration of control A strategic alliance consisting of a bank and a tycoon family could take complete control over Sacombank CONCLUSIONS In this study, using only public available information to calculate, however, we also explain some of the questions surrounding the acquisition history in Sacombank We also point out strategic alliance consisting of a bank and a tycoon family can have complete control over the operation of Sacombank (Before and after the acquisition) -52In order to measure the concentration of control in ownership structure of the banks, we must caculate the control right of the ultimate shareholders in banks Basically, we calculate the Banzhaf indices with direct ownership structures And then, when each new information appears, the impact of it to the Banzhaf indices must be determined untill the best available information is used The accuracy of calculation is depended greatly on the quality of information The better information, the more accuracy result! This method could be useful and applied by state agencies during restructuring the banking system in Vietnam For future work, we will evaluate the advantages and disadvantages of the most powerful shareholders, and their right to vote in high level concentration of control structures to bank risk and banks efficiency ... 15 NG C A C U TRÚC S HI U QU HO H N R I RO VÀ NG C A CÁC NHTMCP ng c a c u trúc s h u lên k t qu ho ng kinh doanh c a NHTMCP thông qua vi c phân b quy n ki m soát C u trúc s h n ho giám sát c a... c hi n giám sát tài s n ng gián ti p c a c u trúc s h u thông qua vi c phân b quy n ki m soát ng c a c u trúc s h u lên k t qu ho ng kinh doanh c a NHTMCP thông qua quy n ki m soát C u trúc s... soát s i di n ng c vào m soát c n y quy n-th a hành gi a c c ngân hàng ng c a c u trúc s h u lên k t qu ho 3.2 Khái quát nghiên c u v m ng kinh doanh c a NHTMCP ng c a c u trúc s h u lên k t