The Efficient Market Hypothesis believes that it is impossible for an investor to outperform the market because all available information is already built into stock prices. However, some anomalies could persist in stock markets while some other anomalies could appear, disappear and re-appear again without any warning. A Special Issue on "Efficiency and Anomalies in Stock Markets" will be devoted to advancements in the theoretical development of market efficiency and anomaly in the Stock Market, as well as applications in Stock Market efficiency and anomalies.

With the rise of digital platforms and the natural tendency of markets involving platforms to become concentrated, competition authorities and courts are more frequently in a position to investigate and decide merger and abuse cases that involve platforms. This report provides guidance on how to define markets and on how to assess market power when dealing with two-sided platforms. DEFINITION Competition authorities and courts are well advised to uniformly use a multi-markets approach when defining markets in the context of two-sided platforms. The multi-markets approach is the more flexible instrument compared to the competing single-market approach that defines a single market for both sides of a platform, as the former naturally accounts for different substitution possibilities by the user groups on the two sides of the platform. While one might think of conditions under which a single-market approach could be feasible, the necessary conditions are so severe that it would only be applicable under rare circumstances. To fully appreciate business activities in platform markets from a competition law point of view, and to do justice to competition law’s purpose, which is to protect consumer welfare, the legal concept of a “market” should not be interpreted as requiring a price to be paid by one party to the other. It is not sufficient to consider the activities on the “unpaid side” of the platform only indirectly by way of including them in the competition law analysis of the “paid side” of the platform. Such an approach would exclude certain activities and ensuing positive or negative effects on consumer welfare altogether from the radar of competition law. Instead, competition practice should recognize straightforwardly that there can be “markets” for products offered free of charge, i.e. without monetary consideration by those who receive the product. ASSESSMENT The application of competition law often requires an assessment of market power. Using market shares as indicators of market power, in addition to all the difficulties in standard markets, raises further issues for two-sided platforms. When calculating revenue shares, the only reasonable option is to use the sum of revenues on all sides of the platform. Then, such shares should not be interpreted as market shares as they are aggregated over two interdependent markets. Large revenue shares appear to be a meaningful indicator of market power if all undertakings under consideration serve the same sides. However, they are often not meaningful if undertakings active in the relevant markets follow different business models. Given potentially strong cross-group external effects, market shares are less apt in the context of two-sided platforms to indicate market power (or the lack of it). Barriers to entry are at the core of persistent market power and, thus, the entrenchment of incumbent platforms. They deserve careful examination by competition authorities. Barriers to entry may arise due to users’ coordination failure in the presence of network effect. On two-sided platforms, users on both sides of the market have to coordinate their expectations. Barriers to entry are more likely to be present if an industry does not attract new users and if it does not undergo major technological change. Switching costs and network effects may go hand in hand: consumer switching costs sometimes depend on the number of platform users and, in this case, barriers to entry from consumer switching costs increase with platform size. Since market power is related to barriers to entry, the absence of entry attempts may be seen as an indication of market power. However, entry threats may arise from firms offering quite different services, as long as they provide a new home for users’ attention and needs.

"The ongoing COVID-19 pandemic marks the most significant, singular global disruption since World War II, with health, economic, political, and security implications that will ripple for years to come." -Global Trends 2040 (2021) Global Trends 2040-A More Contested World (2021), released by the US National Intelligence Council, is the latest report in its series of reports starting in 1997 about megatrends and the world's future. This report, strongly influenced by the COVID-19 pandemic, paints a bleak picture of the future and describes a contested, fragmented and turbulent world. It specifically discusses the four main trends that will shape tomorrow's world: - Demographics-by 2040, 1.4 billion people will be added mostly in Africa and South Asia. - Economics-increased government debt and concentrated economic power will escalate problems for the poor and middleclass. - Climate-a hotter world will increase water, food, and health insecurity. - Technology-the emergence of new technologies could both solve and cause problems for human life. Students of trends, policymakers, entrepreneurs, academics, journalists and anyone eager for a glimpse into the next decades, will find this report, with colored graphs, essential reading.

Financial accounting, reporting and regulation is a vast subject area of huge global importance, with interest rising significantly in the light of the ongoing global financial crisis. The authors begin with a broad overview of the subject of accounting, setting the stage for a discussion on the theoretical and practical issues and debates regarding financial reporting, which are expanded on in the second part of the book. This includes how to define the reporting entity, recognition and measurement of the elements of financial statements, fair values in financial reporting and the costs and benefits of disclosure. The third part assesses the interest, need and theories behind the accounting, reporting and regulation industry, while parts four and five look at the institutional, social and economic aspects; with issues such as accounting for environmental management and, accounting regulation and financial reporting in Islamic countries, both issues of ever increasing importance. This authoritative Companion presents a broad overview of the state of these disciplines today, and will provide a comprehensive reference source for students and academics involved in accounting, regulation and reporting.