Excess market value,market power,and inside ownership structure

This study is an empirical investigation of whether principal-agent problems do in fact significantly affect corporate managers' decision making, and hence the price of the firms' securities. If inside ownership structure of firms is reflected in firm market value, then agency theory leads one to expect that market value will be a positive function of the degree of inside ownership. This study demonstrates that rational investors recognize inside ownership and its resultant effect on market value. Furthermore, it is shown that excess market value as measured by the Tobin's Q-ratio is related to the level of advertising and R&D expenditure, the degree of market power as proxied by the Lerner Index, leverage, and firm size.