2015/16 seasonal vaccine effectiveness against hospitalisation with influenza a(H1N1)pdm09 and B among elderly people in Europe: Results from the I-MOVE+ project

We conducted a multicentre test-negative caseâ\u80\u93control study in 27 hospitals of 11 European countries to measure 2015/16 influenza vaccine effectiveness (IVE) against hospitalised influenza A(H1N1)pdm09 and B among people aged â\u89¥ 65 years. Patients swabbed within 7 days after onset of symptoms compatible with severe acute respiratory infection were included. Information on demographics, vaccination and underlying conditions was collected. Using logistic regression, we measured IVE adjusted for potential confounders. We included 355 influenza A(H1N1)pdm09 cases, 110 influenza B cases, and 1,274 controls. Adjusted IVE against influenza A(H1N1)pdm09 was 42% (95% confidence interval (CI): 22 to 57). It was 59% (95% CI: 23 to 78), 48% (95% CI: 5 to 71), 43% (95% CI: 8 to 65) and 39% (95% CI: 7 to 60) in patients with diabetes mellitus, cancer, lung and heart disease, respectively. Adjusted IVE against influenza B was 52% (95% CI: 24 to 70). It was 62% (95% CI: 5 to 85), 60% (95% CI: 18 to 80) and 36% (95% CI: -23 to 67) in patients with diabetes mellitus, lung and heart disease, respectively. 2015/16 IVE estimates against hospitalised influenza in elderly people was moderate against influenza A(H1N1)pdm09 and B, including among those with diabetes mellitus, cancer, lung or heart diseases

Why Common Ownership Creates Antitrust Risks

The share of stocks beneficially owned by institutional investors has increased substantially over the last three decades. Together with a high and increasing level of concentration in the asset management industry, this trend implies that a small number of institutional investors now constitute the largest shareholders of most publicly traded firms in the U.S. and in other developed economies. When the same set of investors owns most firms, they are bound to own several firms in the same industry. Such overlapping ownership interests among competitors, or “common ownership,” may imply a reduction in firms’ incentives to compete, compared to a situation in which competitors are controlled by separate sets of investors, and may thus create antitrust risks. Recent empirical research shows evidence for such anti-competitive effects of common ownership. These findings have since ignited a debate on the antitrust risk posed by institutional investors, its legal implications and potential solutions. This article first illustrates the extent of present-day common ownership and discusses the economic logic of why common ownership leads to reduced incentives to compete and may cause anti-competitive outcomes. We then review some of the empirical evidence to date, discuss critiques of the same and explain the conceptual problems inherent with all potential policy solutions. The legal debate around these findings is discussed by a fast-growing literature, including contributions by other authors in this issue

Anticompetitive effects of common ownership

Many natural competitors are jointly held by a small set of large institutional investors. In the US airline industry, taking common ownership into account implies increases in market concentration that are 10 times larger than what is “presumed likely to enhance market power” by antitrust authorities. Within-route changes in common ownership robustly correlate with route-level changes in ticket prices, even when we only use variation in ownership due to the combination of two large asset managers. We conclude that a hidden social cost – reduced product market competition – accompanies the private benefits of diversification and good governance