Essays in Empirical Corporate Finance and Corporate Governance

Guided by the observation that ownership in large U.S. corporations is dispersed rather than concentrated in blocks of control (Berle and Means, 1932) and Jensen and Meckling's (1976) seminal principal-agent theory, much corporate governance research has put its focus on the conflict between managers and shareholders and the Anglo-American system of corporate governance. The present thesis provides several contributions to this literature in the substantially different context of the German corporate governance system. Chapter 1. Most existing theories of dividend policy imply that dividend announcements convey value-relevant information to market participants. However, in an efficient market, only the unexpected part of a dividend announcement should contain value-relevant information. The evaluation of the informational content conveyed by dividend announcements therefore crucially relies on the proper modeling of dividend expectations. We find that differences in modeling expectations have severe implications for the investigation of theories explaining the share price reaction to dividend announcements, including agency-based explanations. Chapter 2 provides novel contributions to the literature on dual-class share structures. Rather than focusing on a firm's decision to issue more than one share class, the chapter explores the drivers behind firms' decisions to abandon existing dual-class structures. We exploit a change in the index selection rules of Deutsche Boerse that discriminated against dual-class companies by adversely affecting their relative weight within selection indices. We suggest and empirically support the hypothesis that the change in rules resulted in a trade-off for large controlling shareholders between safeguarding their extant private benefits of control and the costs associated with a loss in index weight. Aside from the concentration of control, the two-tier board structure is another distinctive feature of Germany's corporate governance system. As the name suggests, German corporations are governed by two separate boards: an executive board managing the firm and a supervisory board overseeing management. Frequently, members of the board do not only serve on their own board, but are also simultaneously active in several other outside boards. The literature on busy boards suggests that such additional commitments may put too much strain on the board's resources and thereby adversely affect the compliance with its monitoring duties. Chapter 3 employs methods from social network analysis to explore aspects of board busyness and revisits the relationship between firm governance and the board's position in the network of directors

Index membership vs. loss of voting power: the unification of dual-class shares

A change in the index selection rules of Deutsche Börse provides a unique opportunity to investigate the drivers behind the decision to abolish dual-class shares. As of June 2002, selection is based on the market capitalization of the free-float of the more liquid share class rather than the overall market capitalization. Hence, firms have had to reassess the benefits from their dual-class shares by weighing them against the cost from foregone index weight associated with having two share classes. Our findings suggest that index membership significantly affects the controlling shareholder’s motivation to unify preferred and common stock

Implementation of ultra-hypofractionated radiotherapy schedules for breast cancer during the COVID-19 pandemic in the Netherlands

Background and purpose: The COVID-19 pandemic resulted in an accelerated recommendation to use five-fraction radiotherapy schedules, according to the FAST- and FAST-Forward trial. In this study, trends in the use of different radiotherapy schedules in the Netherlands were studied, as well as the likelihood of receiving five fractions. Materials and methods: Data from the NABON Breast Cancer Audit-Radiotherapy and Netherlands Cancer Registry was used. Women receiving radiotherapy for their primary invasive breast cancer or DCIS between 01–01-2020 and 31–12-2021 were included. Logistic regression was used to investigate the association between patient-, tumour-, treatment-, and radiotherapy institution-related characteristics and the likelihood of receiving five fractions in tumours meeting the FAST and FAST-Forward criteria. Results: Detailed information about radiotherapy treatment was available for 9,392 tumours. Shortly after the start of the COVID-19 pandemic, i.e. April 2020, 19% of the tumours being treated with radiotherapy received five fractions of 5.2 or 5.7 Gray (Gy). While only 3% of the tumours received five fractions in March 2020. The usage of five fractions increased to 26% in December 2021. Partial breast irradiation, compared to whole breast irradiation, was significantly associated with the administration of five fractions, as well as radiotherapy delivered in an academic radiotherapy institution compared to an independent institution. Conclusion: The start of the COVID-19 pandemic was associated with the early use of ultra-hypofractionated radiotherapy schedules. After publication of the trials, and mainly after the recommendation by the national radiotherapy society, the implementation further increased. These schedules were not yet used in all patients meeting the eligibility criteria for the FAST- or FAST-Forward trial.</p

Effects of exercise in breast cancer patients: implications of the trials within cohorts (TwiCs) design in the UMBRELLA Fit trial

Purpose The Trials within Cohorts (TwiCs) design aims to overcome problems faced in conventional RCTs. We evaluated the TwiCs design when estimating the effect of exercise on quality of life (QoL) and fatigue in inactive breast cancer survivors. Methods UMBRELLA Fit was conducted within the prospective UMBRELLA breast cancer cohort. Patients provided consent for future randomization at cohort entry. We randomized inactive patients 12-18 months after cohort enrollment. The intervention group (n = 130) was offered a 12-week supervised exercise intervention. The control group (n = 130) was not informed and received usual care. Six-month exercise effects on QoL and fatigue as measured in the cohort were analyzed with intention-to-treat (ITT), instrumental variable (IV), and propensity scores (PS) analyses. Results Fifty-two percent (n = 68) of inactive patients accepted the intervention. Physical activity increased in patients in the intervention group, but not in the control group. We found no benefit of exercise for dimensions of QoL (ITT difference global QoL: 0.8, 95% CI = - 2.2; 3.8) and fatigue, except for a small beneficial effect on physical fatigue (ITT difference: - 1.1, 95% CI = - 1.8; - 0.3; IV: - 1.9, 95% CI = - 3.3; - 0.5, PS: - 1.2, 95% CI = - 2.3; - 0.2). Conclusion TwiCs gave insight into exercise intervention acceptance: about half of inactive breast cancer survivors accepted the offer and increased physical activity levels. The offer resulted in no improvement on QoL, and a small beneficial effect on physical fatigue.Clinical epidemiolog