银行并购及其规制博弈分析

【作者】 周斌；

【导师】 王文举；

【作者基本信息】 首都经济贸易大学 ， 数量经济， 2011， 博士

【摘要】 在上百年的企业并购史中,企业并购理论得到了充分的发展,但银行并购的特殊性及其影响的复杂性使得一般企业并购理论并不能充分地对其进行解释,而银行并购实践的超前发展又对银行并购理论的形成及发展提出了更高的要求。因此,在立足于企业并购理论及其实践经验的基础上,突破现有企业并购理论的研究框架,从银行主体及业务特色范畴来研究银行并购问题在理论上有创新意义。现代经济学更突出理性人在经济分析中的价值和地位,侧重研究行为过程。博弈论侧重于对多个利益主体的行为特征和规律的分析特点使得博弈论拓宽了经济学的研究领域,加深了经济学的分析。因此,本文应用博弈论来对银行并购及其规制问题进行规范研究。本文首先在概述银行并购的界定与类型、银行产业组织的基础上总结银行并购动因理论。针对并购对银行产业的垄断效应,政府应该对银行并购有相应的规制,本文进一步阐述了相关的并购规制理论。本文的研究分为三个部分：一是从产业方向的角度,针对银行横向并购、纵向并购、混合并购建立博弈模型,分析银行并购的利益驱动机制；二是针对并购的关键因素——并购价格,分别建立博弈模型分析银行协议收购和拍卖竞标这两种并购方式中并购价格的达成机制；三是分析并购对社会福利的影响,进而建立博弈模型分析银行并购的规制问题。基于横向并购的规模经济效应,建立完全信息静态博弈模型进行分析,发现在规模经济制约条件下,如果银行的规模经济指数满足一定的条件,银行之间会发生横向并购。而且,随着行业内银行数量的逐渐增加,使得银行产生并购动机的规模经济指数也逐渐增大,换言之,行业内银行数量越多,银行之间的并购就越容易发生。基于纵向并购的交易成本效应,完全信息博弈模型分析的结论是,处于完全垄断的提供中间产品的银行纵向并购(前向)处于古诺寡头垄断竞争中的生产最终金融产品的银行后,中间产品的市场价格将不会因此而改变,但是最终金融产品的市场价格却得以降低。进一步的探讨则发现,在存在市场圈定的条件下,下游银行的市场地位可以不完全相同,纵向并购银行是否有利可图,并形成行业均衡结构,既要取决于最初银行业中上下游银行的数量,也取决于下游市场结构和下游银行的市场地位。基于范围经济效应,建立完全信息下四个银行分别两两间进行混合并购从而形成两个银行关于两种金融服务提供量的多维博弈模型,并在假设两种金融服务具有可替代性关系的情况下,进一步分析两个银行对两种金融服务联合考虑提供量的多维博弈,其均衡结果要优于不混合并购的均衡结果。从而银行进行混合并购是能获得额外利益的。针对银行协议并购的动态博弈分析发现,无限期完全信息下,谈判双方会轮流出价,直到自己出价被对方接受或自己接受对方出价为止；而无限期不完全信息下,目标银行根据一定的条件提出不同的出价,并购银行则根据自己对时间的偏好程度选择接受或不接受。谈判期间收益的存在,增加了目标银行经营管理层的讨价还价能力,谈判的结果会对目标银行更加有利。而在目标银行保留价值未知的情况下,理论上只要并购银行多次以最小额加价的方式去与目标银行谈判,最终总会有一个价格令目标银行满意,从而保证收购成功。当存在多个并购方相互竞争时,相对于单一并购方,并购方的策略会有很大的变化。在采取密封式第一价格拍卖竞价的情况下,目标银行为了实现利益最大化,对外公布的最低报价会严格大于其私人价值,而并购银行将会采取“隐瞒报价”策略,即并购银行的报价将严格低于其私人价值。并购对社会福利会产生影响,银行并购后的社会福利与并购前后银行数量有关：如果并购前银行数量不低于某个上界值,则并购前银行数量越多,并购后的社会福利越大,说明这个阶段银行之间竞争是低效率的,政府应当鼓励银行并购；如果并购前银行数量不多于某个下界值,并购后的社会福利要小于并购前的社会福利,这意味着并购前银行规模已经较大,再继续并购只会带来规模不经济或者由于银行业的高度垄断致使金融服务价格偏高造成消费者剩余的减少大大超过生产者剩余的增加,此时政府应该限制或者禁止银行并购；如果并购前银行数量位于下界值和上界值之间的区间,则随着并购后银行数量的变化,并购后的社会福利相比并购前的社会福利可能大,也可能小。政府制定并购规则实际上是向银行发出了有关规制成本的信号,银行会以此来判断实施并购的收益。建立信号博弈模型来研究银行并购的规制问题,根据政府规制成本的高低和公布并购规则的宽严程度,博弈的结果出现三种均衡：分离均衡,公布并购规则这一信号可以真实地反映政府的规制成本,高规制成本的政府会选择宽松的并购规则,低规制成本的政府会选择严格的并购规则；混同均衡,规制成本高、低的政府都发出相同的信号——严格的并购规则,银行可能实施并购也可能不实施并购；准分离均衡,高规制成本政府选择严格的并购规则,低规制成本政府以一定的概率选择严格的并购规则,银行的期望收益和均衡策略会随这个概率的变化而变化,并随机选择并购或不并购。更多还原

【Abstract】 In over one hundred years of enterprises’merger and acquisition(M&A), M&A theories have been developed greatly. Because of particularity and complex influence, M & A of banks haven’t been fully explained by common M&A theories. Therefore, there are theoretical innovations to breakthrough existing theories’research frame by studying M&A of banks from banks’behavior mechanism and their service characteristics.Modern economics put more emphasis on rational individual’s value and status, and the behavior process. The game theory deepens economic analysis by stressing on individuals’behavior characteristics and rules. Therefore, the thesis applies game theory to research M&A of banks and related regulation.Firstly, the thesis introduces conception of M&A of banks, M&A types and bank industrial organization. As important theoretical foundations, motivation theories of M&A of banks and theories of regulation are explained with detail afterward.Then the research is conducted from three aspects:(i)Analyzing the benefit actuation mechanisms of horizontal M&A of banks, vertical M&A of banks and mix M&A of banks; (ii)Analyzing how the M&A price is set separately in agreement purchase and auction; (iii)Analyzing M&A’s influence on social welfare and the game between banks and the government in M&A regulation.Based on scale economy effects of horizontal M&A, a complete information static gambling model is established and the analysis discovers that if the bank’s scale economy index satisfies some condition, banks will carry out horizontal M&A. Moreover, it’s more possible if there are more banks.Based on transaction cost effects of vertical M&A, the complete information gambling model draws the conclusion that interim products’price will not change while final financial products’price can be actually reduced after a bank which completely monopolizes interim products merges a bank which provides final financial products in Cournot oligopoly. The further discussion discovers that in the case of market foreclosure, whether banks can benefit from vertical M&A depends on both the quantities of upstream and downstream banks and the downstream industrial structure and the status of downstream bank.Based on the scope economic effects, the thesis establishes a complete information multi-dimensional gambling model in which four banks separately carry out mix M&A merger to form two banks supplying two kinds of substitutive financial service. The outcome of mix M&A surpass that of non-mix M&A, which means banks can obtain additional benefit through mix M&A. Analysis on the dynamic game of bargaining in M&A of banks finds infinite game with complete information will not end until some bank’s offer is accepted by the other, while in infinite game with incomplete information, the bank to be merged will offer according to some conditions and different time-favorite buyers will accept or reject the offer. Incumbent benefit will strengthen the sell’s bargaining competence. While when the buyer doesn’t know about the seller’s reserve value, the buyer can offer an minimum plus value in the negotiation to reach an agreement. As for many buyers in first-price-sealed bid auction, they will offer prices strictly less than their private value while the seller declares an minimum price strictly larger than his private value.M&A of banks affects social welfare. If banks are not less than some upper bound, social welfare will be increased after M&A, which means competence among banks is inefficient so the government should encourage M&A of banks. If banks are not more than some lower bound, social welfare will be decreased after M&A, which means M&A will cause scale diseconomy or high monopoly results in the decrease of consumers’surplus greatly surpassing the increase of producers’ surplus so the government should restrict or forbid M&A of banks. If the quantity of banks is between the lower bound and the upper bound, social welfare after M&A of banks may be increase or decreased.The government makes M&A rules, which sends out the government’s regulatory cost, and banks can judge their benefits through M&A. A signaling gambling model is established to research regulation on M&A of banks. According to the government’s regulation cost and regulation rules, the game will reach three kinds of equilibrium: (ⅰ)Separating equilibrium, in which the government with high regulation cost makes loose M&A rules while the government with low regulation cost makes strict M&A rules. (ⅱ)Pooling equilibrium, in which the government makes strict M&A rules regardless its regulation cost. (ⅲ)Partially separating equilibrium, in which the government with high regulation cost makes strict M&A rules while the government with low regulation cost makes strict M&A rules by certain probability.更多还原