Reason: College grads are more likely to get vaccinated against COVID than non-grads. Leading to a reduction in symptom severity and perhaps long covid.
But there could be other causes. You are operating under the default assumption long COVID must exist. But non-grads on average are poorer, work in different environments, and have different health (i.e. obesity and diabetes) than grads. There could be any number of underlying health conditions causing brain fog and other long COVID symptoms. Obesity and diabetes are known to impact brain function and are correlated with Alzheimer's. Sedentary lifestyles and poor diet can also lead to low energy.
The reason I say placebo is because any of these pre-existing conditions could be blamed on long COVID. Think about it: you don't know much about diseases, you see CNN/Fox News/MSNBC talking about long COVID. You think to yourself, hey I've got those symptoms! You blame long COVID, even though the underlying cause could have been obesity, diabetes, sedentary lifestyle, diet, etc.
We know obesity is harmful yet the fat acceptance movement exists. Do you think those people are going to blame their symptoms on their obesity?
Reason: College grads are more likely to get vaccinated against COVID than non-grads. Leading to a reduction in symptom severity and perhaps long covid.
https://healthpolicy.usc.edu/evidence-base/education-is-now-...