Wolfgang Drobetz

This study presents a systematic comparison of portfolio insurance strategies. We implement a bootstrap-based hypothesis test to assess statistical significance of the differences in a variety of downside-oriented risk and performance measures for pairs of portfolio insurance strategies. Our comparison of different strategies considers the following distinguishing characteristics: static versus dynamic protection; initial wealth versus cumulated wealth protection; model-based versus model-free protection; and strong floor compliance versus probabilistic floor compliance. Our results indicate that the classical portfolio insurance strategies synthetic put and constant proportion portfolio insurance (CPPI) provide superior downside protection compared to a simple stop-loss trading rule and also exhibit a higher risk-adjusted performance in many cases (dependent on the applied performance measure). Analyzing recently developed strategies, neither the TIPP strategy (as an ‘improved’ CPPI strategy) nor the dynamic VaR-strategy provides significant improvements over the more traditional portfolio insurance strategies.

Embracing the concept of factor investing, we design a flexible framework for building out different factor completion strategies for traditional multi-asset allocations. Our notion of factor completion comprises a maximally diversified reference portfolio anchored in a multi-asset multi-factor risk model that acknowledges market factors such as equity, duration, and commodity, as well as style factors such as carry, value, momentum, and quality. The specific nature of a given factor completion strategy varies with investor preferences and constraints. We tailor a select set of factor completion strategies that include factor-based tail hedging, constrained factor completion, and a fully diversified multi-asset multi-factor proposition. Our framework is able to organically exploit tactical asset allocation signals while not sacrificing the notion of maximum diversification. To illustrate, we additionally embed the common trend style that permeates many asset classes, and we also include the notion of style factor momentum.

Recent empirical research shows evidence of a positive relationship between the quality of firm‐specific corporate governance and firm valuation. Instead of looking at one single corporate governance mechanism in isolation, we construct a broad corporate governance index and apply five additional variables related to ownership structure, board characteristics, and leverage to provide a comprehensive description of firm‐level corporate governance for a representative sample of Swiss firms. To control for potential endogeneity of these six governance mechanisms, we develop a system of simultaneous equations and apply three‐stage least squares (3SLS). Our results support the widespread hypothesis of a positive relationship between corporate governance and firm valuation.

New evidence from acquisition decisions suggests that antitakeover provisions (ATPs) may increase firm value when internal corporate governance is sufficiently strong. We document that, in Germany, firms with stronger ATPs, and particularly supermajority provisions, are better acquirers. Managers of high-ATP firms create value in acquisitions by making governance-improving deals. They are more likely to engage in acquisitions that reduce their own entrenchment level and less likely to invest in declining industries. The empirical evidence is consistent with a short-termist interpretation. Takeover threats can induce myopic investment decisions, which ATPs can mitigate. They lead managers to engage more often in value-creating long-term and innovative investing, and increase a firm's sensitivity to investment opportunities. Our findings contribute to a growing literature challenging conventional wisdom that the agency-increasing effect of ATPs empirically dominates the myopia-eliminating effect, suggesting that a more contextual view of the value implications of ATPs is necessary.

The old and simple investment strategy “Sell in May and Go Away” (also referred to as the “Halloween effect”) enjoys an unbroken popularity. Recent studies suggest that the Halloween effect even strengthened rather than weakened since its first publication by Bouman and Jacobsen (2002). We implement regression models as well as Hansen’s (2005) “Superior Predictive Ability” test to analyze whether stock markets are really so inefficient. In line with the predictions of market efficiency, our results reject the hypothesis that a trading strategy based on the Halloween effect significantly outperforms.

Research Question/Issue: This paper reviews key theories on the governance role of institutional investors, examines institutional ownership trends globally, and highlights recent research on their evolving impact on corporate governance. The paper also incorporates insights from select Special Issue articles dedicated to understanding the role of institutional investors worldwide.Research Findings/Insights: We show that while most existing research focuses on the United States, recent evidence highlights significant global growth in institutional ownership. However, research examining the role of institutional investors outside the United States remains limited, despite some recent progress.Theoretical/Academic Implications: Institutional investors are increasingly shaping global capital markets and corporate governance through growing ownership, increased shareholder activism, and rising passive investment strategies. We provide recommendations for relevant topics to guide future research, including the governance preferences of institutional investors (i.e., voice vs. exit) across different investor types and international settings, as well as the collective influence of multiple institutional investors on corporate governance practices and outcomes.Practitioner/Policy Implications: There is a meaningful need for future studies to address the influence and effectiveness of institutional investors on corporate governance practices around the world. A better understanding of their role in different settings should improve their impact on corporations and, more broadly, on society.

This paper examines how institutional investors exchange private information through co-shareholding networks and the implications for corporate acquisition outcomes. Using New York City taxi data, we identify face-to-face interactions among investor pairs and document that co-blockholders are more likely to seek on-site meetings, consistent with an increased exchange of information. Given evidence for an information channel, we construct the broader blockholder network between US institutional investors and show that acquirers held by more centrally positioned institutional investors earn higher announcement returns. The valuation effect is strongest when targets are more opaque and private information is more valuable. Consistent with an advisory channel, the effect only exits among investors with a comparative advantage in exploiting information, and facilitates “hidden gem” acquisitions rather than preventing poor deals. Overall, our findings suggest that co-shareholding networks promote private information flows that translate into superior advice and enhance M&A performance.

This paper examines the relationship between board diversity and firms’ decisions to voluntarily disclose information about their greenhouse gas (GHG) emissions. We focus on board ancestral diversity as a relatively new dimension of (deep-level) board structure and document that it has a positive and statistically significant effect on a firm’s scope and quality of voluntary GHG emission disclosure. The effect goes beyond the impact of more common (surface-level) dimensions of board diversity and remains robust after addressing endogeneity concerns. In line with the theoretical conjecture that diversity enhances a board’s advising and monitoring capacity, we find that the impact of diverse boards is stronger in more complex firms and in firms with low levels of institutional ownership. Overall, our findings provide evidence for board diversity being a relevant governance factor in corporate environmental decision making.