• Dr. Ferguson

Correlation is Not Always an Indicator of Causation

When two facts are related, sometimes one causes the other. But causation is not always present when facts are correlated.

Parts of the country with large numbers of cell phone towers are parts of the country with large numbers of COVID-19 cases. That fact is undeniable. Maps of US cell phone tower density and maps of US COVID-19 cases line up almost perfectly. So do cell phone towers cause COVID-19? Or at least, do cell phone towers increase the risk of contracting COVID-19? It is imaginable that cell phone towers increase the risk of COVID-19 infection, but the data do not support that conclusion. In fact, maps of US population density line up perfectly with maps of COVID-19 cases and maps of US cell phone tower density. Of course, places with more people will tend to have more total COVID-19 cases and have more total cell phone towers. Imagine a 100 acre section of California’s Mojave Desert. It is so far away from the nearest cell phone tower that there is no chance of cell phone reception. It is so far away from human activity that it’s been years since any human has entered that 100-acre plot of land. And now imagine that there are no COVID-19 cases reported in that place. Is the lack of cases related to the lack of cell phone towers? Or is it related to the fact that there are no possible cases because there are no people there?