The nineteenth-century theorists of modern Romanist dominium, the great French treatise writers and the German Romanists, embarked in a quest for coherence, aspiring to develop a body of property law that was both normatively and conceptually coherent. These jurists sought to build an architecture of logically interrelated property doctrines informed by the unifying commitment to maximizing the owner’s freedom of action. Yet, this coherence was illusory. Far from being coherent, modern property was riven with tensions that could hardly be disguised. This chapter examines the jurists’ attempts to deal with four doctrines that threatened to strain the coherence of the property system: emphyteusis, possession, the limits on ownership and common ownership. While ultimately unsuccessful, these attempts are nonetheless worth exploring. For one thing, these failed attempts opened rifts in the apparently solid edifice of modern dominium, rifts that, a couple of decades later, the social critics will be quick to exploit. Most importantly, the jurists’ efforts to ease these tensions throw into sharp relief a diversity of ideological and methodological views that hardly surfaces in the nineteenth-century property treatises.

US academic discourse on director interlocks isn’t new. Yet, the increased attention to common ownership has also brought to light the increased tendency of interlocked directors to serve in the same industry. I termed these directors as horizontal directors in my earlier work – shining a light on the benefits they bring to investors and companies but also the risks they pose to corporate governance and antitrust law. This chapter further revisits the prevalence of horizontal directors, armed with six additional years of data, and shows that the prevalence of horizontal directors has remained steady, even as attention to common ownership has increased in recent years. These findings should serve as a clarion call to regulators – urging them to directly address the perils of horizontal directors while maintaining some of their key benefits.

Common ownership is the talk of the town in antitrust land. The competitive implications of rival firms being partially owned and controlled by a small set of overlapping owners are both fascinating and hotly contested. Could the source of potential harm be minority shareholder control in a setting of widely held companies? Critics question the extent and mechanisms of common owners’ influence driving any pro- or anticompetitive effects. This chapter aims to present a comprehensive account of partial ownership, capturing the incentives and effects of both individual and institutional investors and also cross- and common shareholding. It illustrates the early historical unity between corporate and competition laws in regulating shareholding acquisitions but also their progressive quiet disconnect. Triggered by the contemporary common ownership (hypo)thesis, it puts forward a taxonomy of shareholding types and their control characteristics from a competition law perspective, with emphasis on commonly thought passive and diversified investment holdings. The chapter concludes by urging competition and corporate governance and finance policymakers towards harmonic regulatory solutions to address common ownership. It also offers a quantum theory of the corporate property “atom”, drawing cautionary tales about the dynamic and ambiguous qualities of minority common shareholding for antitrust enforcers.

A stylized fact that lurks in the background of the recent literature on common ownership is the parallel increase in the profitability of oligopolistic industries and common ownership. Some have argued that the growth in common ownership has caused the increase in oligopoly profits and have proposed a variety of policy responses. This paper briefly reviews the available evidence and finds it unconvincing. It then provides an overview of the evidence that concentration and profitability have increased, considers alternative explanations, and suggests that the emergence of “superstar” firms – and not the growth in common ownership – could be a fundamental driver of the parallel increase in concentration and profitability.

Recent literature on common ownership has employed econometric findings on the correlation between parallel holdings and prices on specific product markets to support policy claims directed to intervene in the investment strategies of the worlds largest investment corporations. Regardless of the validity of such econometric findings, direct intervention in the investment strategies of large investment management corporations may produce a series of unwanted negative repercussions on the positive externalities that are correlated to the presence of parallel holdings (e.g. enhanced pursuance of ESG objectives) without actually sorting out the expected pro-competitive effects – because of the presence of other co-causation factors that determine price increases. Sound policy interventions should also consider the larger picture (concentration on the product markets, concentration on the financial services market, status of governance practices and policies and finally also geopolitical variables) before embarking in any policy strategy in this field.