【正文】 tolerance towards risk(Demsetz and Le。Becht and Roell,1999).Consequently ,the potential expropriation of the minority investors by the controlling owners became the main concern(Johnson et al.,2000,Faccio and Lang,2002。附 錄AOwnership concentration and firm performance:Evidence from an emerging marketBy: Irena GrosfeldAbstractThe initial view of the advantages of ownership concentration in joint stock panies was determined by the concern about the opportunistic managerial behavior. The growing importance of knowledge and human capital in the operation of firms shifts the focus of concern: excessive ownership concentration may stifle managerial may be particularly true, and the results obtained in this paper support this hypothesis, in firms with high share of knowledge related activities. I explore the determinants of ownership concentration and the relationship between ownership structure and firm value in the context of a transition economy, . an economy undergoing important changes in its legal and regulatory framework, in macroeconomic policy and most of all, in its property rights allocation. I focus on all nonfinancial panies traded on the Warsaw Stock Exchange since its inception in 1991 up to 2003. The ownership structure of these panies bees more dispersed with the number of years of listing. The results give support to the hypothesis that firms belonging to the sector of high technology have lower ownership concentration than firms in more ‘mature’ industries. The positive impact of ownership concentration on firm value detected in OLS regressions bees even stronger when we control for the endogeneity of ownership.Keywords : Ownership structure, corporate governance, uncertainty, knowledgeeconomyWhat are the characteristics of‘good’ownership structure?Does ownership structure matter for firm performance?Why certain firms have large block holders and others do not?Should the power of large shareholders be limited to avoid expropriation or enc ouraged to curb managerial discretion?These questions have been largely explored in corporate finance literature and we understand better now the intricacies of the relationship between ownership structure and firmperformance.But empirical evidence on the impact of shareholders with significant equity holdings oncorporate performance remains authors using different samples of firms and different empirical strategies obtain different,difficult to pare and sometimes contradictory is increasingly recognized that the problem in disentangling this relationship is largely due to the pervasive endogeneity of ownership which has to be taken into account in order to obtain unbiased the existing empirical evidence also suggests that the relationship between ownership and performance may depend on the type of the firm and on the period of observation in the life of the firm.The purpose of this paper is to explore more in details the determinants of ownership concentration and the relationship between ownership structure and firm value in the context of an economy undergoing important changes in its legal and regulatory frame work,in macroeconomic policy and most of all,in its property rights a panel of firms listed on the Warsaw Stock Exchange(WSE)offers an unusual opportunity for this kind of investigation.The Polish economy was exposed to radical institutional changes in the strategy in Poland was strongly influenced by the willingness to create appropriate ownership structure in privatized firms, ensure that powerful block holders control the large portion of stateowned enterprises was privatized and the conditions for entry of new firms were signific antly of the privatized and newly created firms have entered the stock exchange established in firms are likely to show a lot of ownership structure is likely to be determined by the firm origin and for privatized firms by the method of firms,when they bee listed on the stock exchange are likely to have,at least during the initial years of listing,more concentrated ownership structure than privatized ,new firms established by their founders in a market friendly environment may require less ownership,financial and industrial restructuring than previously stateowned enterprises.The sensitivity of firm performance to firm ownership structure is likely to vary across may also undergo important changes over firms are listed on the stock exchange,reallocation of ownership stakes bees greatly first part of this paper is devoted to the exploration of the determinants of ownership to understand why certain firms have large owners and others have dispersed ownership structure,I build on the extant literature and notably on Demsetz and Lehn (1985)and Himmelberg et al.(1999).The contribution of my paper to the literature consists in taking into account the importance of knowledge related activities.The idea is that analyzing the relationship between managers and shareholders requires different perspectives in firms belonging to the sector of“new economy”than in firms belonging to more traditional industries4 (Audretsch and Lehmann,2002).In more‘mature’industries,it can be assumed that it is well understood what should be done and how and it is important to make sure that managers implement efficiently the objectives agreed such conditions,the dominant concern is indeed about managerial shirking,laziness and laxity(Marshall,1923).Such concern motivates the importance and high value of firms with strong human capital ponent,it is less clear what is the right strategy or the right managers to do a particular thing may be costly since shareholders may not know what the best thing to do such highly uncertain environment,(‘uncertain’in the sense of Knight),the crucial issue is less to make sure that the agentmanager realizes a given objective with a maximum effort than to incite the manager to search for the