In these difficult times, we’ve made a number of our coronavirus articles free for all readers. To get all of HBR’s content delivered to your inbox, sign up for the Daily Alert newsletter. The Covid-19 pandemic is constantly evolving, with leaders facing unpredictability, imperfect information, multiple unknowns, and the need to identify responses quickly — all while recognizing the multi-dimensional (health-related, economic, social, political, cultural) nature of the crisis. Responding to the crisis requires adaptive leadership, which involves what we refer to as the 4 A’s: All of the 4 A’s are plain to see in the most successful responses to the pandemic. Take the pharmaceutical firm AstraZeneca. Thanks to their large Chinese operations, they learned about the virus early, and started working to anticipate future needs and issues, while also navigating the considerable uncertainties and unknowns. They articulated these needs to a wide range of internal and external stakeholders to garner commitment and support, and adapted a range of new business models and partnerships to effectively meet the most urgent Covid-19 needs — most notably vaccine development, but also testing and screening methods, health facility development, and the use of AI to support diagnostics and case management. Perhaps most notably, the firm has established an inclusive approach to accountability, with a commitment to support the global Covid-19 response “as economically and as equitably” as possible — including numerous agreements for the large-scale production and distribution of any successful vaccine at zero profit during the period of pandemic....

The SEC Chairman recently announced a policy initiative to enable the ordinary investors to invest in private companies. Currently, only wealthy accredited investors are allowed to invest in private companies. His stated goal is enabling small investors to get access to alternative high-quality investments, such as in private tech companies like Uber and AirBnB. But in our view this policy, even if implemented, will not work as intended because the ordinary investors may not want to invest in private startups and private companies, especially digital ones, may not want ordinary investors....

Government responses to the Covid-19 pandemic have closed down a significant portion of the global economy, creating severe liquidity problems for many companies at a time when the corporate sector is historically highly leveraged across the board. So while the 2001 and 2008 economic downturns put only a relatively limited number of companies under serious cash-flow pressure — those that were both leveraged and whose earnings were sensitive to the economic cycle — the current crisis has left swathes of companies scrambling for cash....

What happens when index funds run Corporate America? Hedge fund activist Bill Ackman posed that question recently in his fund’s annual letter to investors. It’s a really good one. No one knows what consequences the boom of passive investment funds will have for the corporations they own. It’s something my coauthors and I explore in a forthcoming research paper, and our conclusion goes against the prevailing wisdom. After all, since 1998 the share of assets held by passive institutional investors — mutual funds designed to track stock indices like the S&P 500 rather than actively picking winners — has tripled. Last year clients poured an additional $414 billion into U.S.-based, lower-cost index funds offered by Vanguard, BlackRock, State Street, and others. At the same time, clients withdrew $207 billion overall from actively managed funds, according to the research firm Morningstar. The assets of BlackRock alone are now larger than the GDPs of all but two countries. The rise of mutual funds designed to mimic stock indices rather than outperform them seems destined to change the dynamic of company boardrooms and executive suites. Since passive investors have dramatically more assets under management, they might be expected to exert more influence over corporate decision making....