Below is a really poor graphic put together by NBC (find HERE). All I can figure is that a young data scientist somewhere within the bowels of NBC wanted to present a story about the dangers of not locking down a state and therefore consciously or unconsciously laid out a graph that would confirm their intuition. My hope is that presenting a comparison of how NBC approached this data with my more careful representation of the same data will help people recognize particularly manipulative data presentation.
Below is what NBC presented:
Maybe the problems with this are obvious. Perhaps it’s true that states that never issued a lockdown order are especially hard hit right now, but this chart does not make that case, as 1) it just compares these states to each other, 2) it uses narrow, one-month time scales, an approach that makes the curves look very alarming, and 3) it doesn’t normalize the cases by population. Lots of cases in a very large region doesn’t equal a few less cases in a very small region. Obviously that second, smaller, region is going to be having a more difficult time. See below where I have taken this same data, normalized by population, and compared to a range of other states of different sizes with Governors of either party. I leave NY off intentionally so as not to dwarf the other states.
Here is How I Present the Same Data
What do we see in the second chart? When we compare the “non-lockdown” states to other states, we see that a couple of them (Nebraska, SD) are comparable to the relatively-hard-hit Illinois, but the others are more comparable to less-hard-hit states like Arizona, Kentucky, and Texas. A quick google shows me that the cases in Nebraska and SD are largely driven by super-spreader activities at single meat-packing plants in each state. Perhaps a lockdown would have prevented this, but that bears more research. Looking at Nebraska vs. Illinois, we see two very different approaches to COVID-19. Nebraska is a small state that did no lockdown. Illinois is a larger state with big cities that is still on lockdown as of today’s date. As you can see, both of these states have a very high case growth slope (while New Jersey and South Dakota seem to be decelerating). Hopefully I’m making the point that being honest with the data and taking a scientific approach to presentatin of data is better for all of us. It is less sensational and more representative of what is actually happening. Plus, it doesn’t drive any false narratives.