Over the past week or so, echoing public health officials & epidemiologists, I’ve been trying to illustrate the often counterintuitive concept of exponential growth that you see in an epidemic and how flattening the curve can help keep people healthy and alive. But I think people have a hard time grasping what that means, personally, to them. Like, what’s one person in the face of a pandemic?

Well, epidemiologist Britta Jewell had a similar thought and came up with this brilliantly simple graph, one of the best I’ve seen in illustrating the power of exponential growth and how we as individuals can affect change:

Jewell explains a bit more about what we’re looking at:

The graph illustrates the results of a thought experiment. It assumes constant 30 percent growth throughout the next month in an epidemic like the one in the U.S. right now, and compares the results of stopping one infection today — by actions such as shifting to online classes, canceling of large events and imposing travel restrictions — versus taking the same action one week from today. The difference is stark. If you act today, you will have averted four times as many infections in the next month: roughly 2,400 averted infections, versus just 600 if you wait one week. That’s the power of averting just one infection, and obviously we would like to avert more than one.

So that’s 1800 infections averted from the actions of just one person. Assuming a somewhat conservative death rate of 1% for COVID-19, that’s 18 deaths averted. Think about that before you head out to the bar tonight or convene your book group as usual. Your actions have a lot of power in this moment; take care in how you wield it.