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What Covid-19 has taught us about exponential change and why this is important for the future

It has been suggested that the rapid spread of the Omicron Covid-19 variant is because of its capacity to shorten doubling times in infections. Doubling is a characteristic of exponential change which has been described as ‘unintuitive’ (or counter-intuitive), which means it can easily distort consequential judgements by leaders as to when and how to act effectively. They tend to act too late, and then overshoot.

Human thinking exhibits a bias towards linear change which leads people to often treat exponential growth as if it was going to be linear, and this is of course dangerous when it does not turn out to be so. Growth that multiplies and then multiplies again for a period of time (exponential), is very different to growth that is additive, building incrementally in equal chunks over time (linear). In the case of the Covid-19 pandemic in the UK, treating the exponential growth of the virus as if it was linear has often miscommunicated a true account of the situation to citizens, and complicated public policy responses. For example, a wait and see or ‘gradualist’ approach in the early stages - a course of action well suited to linear growth – caused a number of problems including not scaling up an effective community testing and response system quickly enough. 

Developing ways to counter the human bias against taking exponential growth seriously is not only essential for successfully addressing a pandemic like this, but also to successfully engage with other future issues characterised by such change. An example is the impact of continuing with a ‘business as usual’ economic growth trajectory as the exponential changes of climate change ramp up. 

Early in the pandemic we noticed the disorientation and miscalculations that exponential growth patterns can cause. Since then, we have been working with public and private sector leaders to assess how exponential growth can be better addressed. 

This is what we have learnt:

  • Be discerning about growth trajectories. Is the nature of what you are dealing with more characteristic of exponential or linear change? One quick way of assessing this is to see if the growth is multiplicative (exponential growth) or if the growth is increasing by constant amounts (linear change). Exponential examples include stories that go ‘viral’ on social media; technologies that ‘disrupt’; invasive species (including pests) that ‘multiply’ beyond the control of the host population; and compound interest rates that make debts ‘sky-rocket’. 
  • Acknowledge and validate the experience of unfamiliarity and disorientation that exponential growth can cause. This experience was particularly evident at the beginning of the pandemic with many leaders unsure how to make sense of what was rapidly unfolding. Coming to understand their exponential bias helped them to realise that the confusion was not only derived from the pandemic per se but from their more linear expectations about how growth unfolds which the pandemic did not so easily comply with.
  • Use scenarios to become familiar with the potential impact of exponential changes. Plausible scenarios of the future context enable leaders ahead of time to explore the potential impact of such growth. In this tradition, scenarios are opportunities to explore and learn thereby helping leaders ‘settle in’ to potentially unfamiliar futures and to trial different policy and strategy responses. For example, preparing for the next potential pandemic.
    • Pay particular attention to communications. Be careful not to extrapolate exponential growth figures without acknowledging that they will peak at some point. And where relevant, use language and concepts that are more widely known to explain growth trajectories. For example, the story of the lily pond (where one lily emerges on day one, doubling every day until the pond is half covered on the 47th day and completely covered on the 48th day) can be a helpful way to convey exponential growth, while a straight line trending up can explain linear change – or even showing the contrast in the shape of the curves as in the visual above.   
    • Appreciate the need for resilience in systems. Exponential growth can be experienced as a shock that will stress and expose fragilities in systems in ways that linear change may not. The pandemic for example has exposed stress points in the UK National Health Service, as well as just-in-time supply chains. Assessing what aspects of a business or society are subject to exponential growth will help to focus attention on those aspects of a system that need reinforcing.

    Trudi Lang is Senior Fellow in Management Practice and Rafael Ramirez is Professor of Practice at Saïd Business School, University of Oxford. They have previously written on exponential growth and scenario planning and lead the Oxford Scenarios Programme.