COVID-19: Exponential Growth and the Myth of the Balanced Response

by Raywat Deonandan

April 27, 2021

A slightly modified version of this article was published in The Ottawa Citizen with the title, “Deonandan: COVID-19 — How Ontario fell into the myth of the balanced response” on April 28, 2021.

Earlier this month, Ontario’s Solicitor General Sylvia Jones was asked on a radio show why the province waited so long before enacting the COVID-19 restrictions that doctors and scientists had been pleading for. Earlier, Ontario’s Science Table had observed a worrying growth trend in cases and ICU usage and had forecasted a dire and explosive situation just mere weeks away.

Jones replied, “We wanted to make sure that the modelling was actually showing up in our hospitals.”

This was a curious answer that speaks to the heart of the issue of slow and ineffective government responses to the pandemic. It is also why the so-called “balanced response” advocated by those seeking to calibrate public health responses against real-time data was always doomed to failure.

The problem, simply, is exponential growth. Most of us do not understand it. In a pandemic, that failure of understanding is our undoing.

Investors know it as compound interest. Consider the unlikely but delectable scenario in which you pay a single dollar into an investment fund that guarantees to double your money every three days. How long will it be before you become a millionaire? You might be shocked to know that it would only take sixty days. That is the insidious magic of exponential growth.

Similarly, a small number of COVID-19 cases can explode into a nightmarishly overrun healthcare system in a matter of weeks. If you wait until you see the modelling in the hospitals, it is probably too late to prevent the crisis.


The human brain thinks naturally in terms of linear growth, possibly developed through millennia of evolution chasing prey and escaping from predators who tend to move at constant speeds over a given period. It is why we can easily predict where a vehicle or a running animal will cross our path if it does not change course or accelerate.

But we struggle to internalize exponential growth, which can be deadly when responding to an infectious disease. A 2020 paper by German statisticians suggested that, “people mistakenly perceive the coronavirus to grow in a linear manner, underestimating its actual potential for exponential growth.” The authors go on to say that this cognitive failure, “influences political opinions about matters of life and death.”

Exponential growth comes in two phases. As labelled by author Richard Baldwin, the first is the “imperceptible progress” phase and the second is “explosive progress”. In the first phase, growth is acknowledged but easily dismissed. But in the second phase, we are overwhelmed by growth and act surprised that it is happening at all.


Futurist Roy Amara lends his name to Amara’s Law, which states, that “we tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run.” This is because technologies tend to grow exponentially, and we salivate over their unrealized potential early on –the imperceptible progress phase– but are shocked when that potential is actualized and overwhelms us in the explosive progress phase.

For example, the growth in the speed of computers in the past couple of years has been twice that of the previous fifty years. Baldwin argues that that is why Artificial Intelligence suddenly seems so daunting, though its rate of development has been steadily on an exponential curve for years.

We can see Sylvia Jones falling into the trap of Amara’s Law. By waiting to see if the explosive growth of COVID-19 shown by the provincial modelling would manifest in the hospitals, the province was in essence doing nothing during the “imperceptible progress” phase of the 3rd wave. So here we are, overwhelmed in the “explosive progress” phase.

The lesson of exponential growth as it pertains to public health is this: When we know it is happening, when we are still in the “imperceptible progress” phase, we must act decisively. If we wait until the “explosive progress” phase, we risk not having the resources to mount a sufficient response.

In other words, our response must always feel like a premature overreaction, or else it will never be enough.

Raywat Deonandan is an Epidemiologist and Associate Professor with the Faculty of Health Sciences, University of Ottawa