The Covid-19 outbreak has exposed the thin margins on which much of global business runs. Highly indebted companies, working from lean inventory, supported by just-in-time supply chains and staffed by short-term contractors, have borne the brunt of the sudden blow. They will now suffer the rolling, longer-term impact of its unpredictable consequences. Too late, many executives and owners have realised that by pursuing the holy grail of ever greater efficiency, they sacrificed robustness, resilience and effectiveness. In many cases, they will turn out to have sacrificed the business itself.

As managers wrestle with how to restart production lines and restaff offices, they must also consider how to prepare for inevitable future shocks. These include not just a resurgence of this virus but different, perhaps more dangerous, pandemics, or the longer-term disruption of climate change. Like the banks after the global financial crisis, businesses will need to build thicker buffers against shocks. If they do not, governments and regulators will need to find ways to encourage or oblige them to shore up their defences.

At least in the short term, investors will help by shunning fragile business models. Equity and bond markets are already discriminating sharply in favour of fundraising requests from companies with strong balance sheets and high credit ratings. Jim Chanos, the US investor, warned last month he was shorting the stock of companies that relied on “gig workers”, on the basis that the crisis would change social and political attitudes to businesses relying on this precarious workforce.