Corporate governance, corporate diversification and ownership structure.

Summary The objective of this thesis is to study the role that firm diversification and ownership structure play in the value creation process. The second chapter is devoted to a literature review of theoretical and empirical works that analyze the impact of ownership structure and firm diversification on the market value of firms. The third chapter deepens the analysis of firm diversification by studying the interaction effect between product diversification and international diversification. This chapter considers the relationship between diversification and capital structure in a sample of Italian manufacturing firms. Our findings allow us to argue that this interaction effect has a negative impact on debt capacity. Finally, the fourth chapter studies the impact of a multiple shareholder structure on firms' risk taking. The analysis is conducted on firms listed on the US financial market. Most previous studies on ownership structure focus on the differences between firms with at least one reference shareholder versus firms with scattered ownership, without considering the potential effect of multiple blockholders on stock volatility and performance. We show that blockholders play an important role in mitigating conflicts of interest between majority and minority shareholders.