just because you have a PhD doesn’t mean you can’t learn something new. If you don’t believe that you’re not so bright.
I simply cautioned you about extrapolating on data. Then you threw the PhD card. Kind of like liberals throwing the race card. You know more than me, or so you imagine. Like I said, carry on PhD.
PS - R-squared, the square of the fit residuals, will grow, not decrease, once your curve breaks. That’s when your poly breaks down. The poly trajectory is less steep than the exponential trajectory, so when it breaks to fewer cases, going exponential is the wrong direction. You don’t even understand the basic math behind the excel formulas. A common mistake for most people who become excel experts, but for a studied PhD, a sign of over confidence or a failing education system.
Once again, you are attempting to shove a square peg into a round hole. Once the pandemic starts to break and the curve reaches an inflection point, my first indication is going to be a DECREASE in the R squared value, as the data points no longer land on the curve. It won’t cause an increase to values that are already 0.98-0.99. At that time, and ONLY at that time would it be worth the effort to derive an exponential function to describe the curve. Why on earth would I do all of that work now, when I already have years of experience telling me that the polynomial gives values within a few thousandths of the real values, well within any margin of error?
I get the feeling that you’re trying to demonstrate that you have more knowledge than an actual expert in the field. You don’t. The desire to do that is well-known as the Dunning-Kroger effect.