Bank Underground is a blog for Bank of England staff to share views that challenge – or support – prevailing policy orthodoxies. The views expressed are those of the authors, and are not necessarily those of the Bank of England, or its policy committees. Posting on this blog, Adam Brinley Codd and Andrew Gimber argue that false confidence in people’s ability to calculate probabilities of rare events might end up worsening the crises regulators are trying to prevent.
The post concludes with their personal observations about how best to deal with this meta-uncertainty.
Policymakers could avoid talking about probabilities altogether. Instead of a 1-in-X event, the Bank of England’s Annual Cyclical Scenario is described as a “coherent ‘tail risk’ scenario”.
Policymakers could avoid some of the cognitive biases that afflict people’s thinking about low-probability events, by rephrasing low-probability events in terms of less extreme numbers. A “100-year” flood has a 1% chance of happening in any given year, but anyone who lives into their 70s is more likely than not to see one in their lifetime.
Policymakers could be vocal about the fact that there are worse outcomes beyond the 1-in-X point of the distribution.