I’ll try one more time.
A trend line not going down is not proof your actions had no effect on the trend line.
This is one of those sentences that seems simple, but takes a little bit of thought to get it right, so let’s walk through it slowly together.
We are watching a trend line that is rising - meaning, going up on the y axis as it moves to the right on the x axis.
To alter the trend, we do ‘X’.
The trend continues to rise.
What can we conclusively say?
- ‘X’ did not make the trend level off or go down. That is true.
But can we say ‘X’ had no effect on the trend line? No. We can not say that.
Why not?
Because we do not know what the trend line would look like in the absence of ‘X’.
In the absence of ‘X’ the line might have risen FASTER. Or, conceivably, in the absence of ‘X’ the line might have fallen to zero. Who knows?
Since this is a real time experience, we can not go back in time and eliminate ‘X’ and no for sure what would happen to the trend line.
Is that understandable?
A trend line not going down is not proof your actions had no effect on the trend line.
Now, if you are with me so far, let’s wander into extra credit territory.
Imagine a situation where you COULD go back in time, and you COULD watch the trend line again IN THE ABSENCE OF ‘X’! Then you could answer the question, couldn’t you? You would know if ‘X’ was having an effect on the trend line. If, as you suggest, the trend not going down means your actions had no effect.
We can in fact do this with computer modeling.
If you are still with me, we can walk through, step by step, what computer modeling is, and how we can use it to answer the real life question we were discussing before we had to slow things down.
But here, spoiler alert: Computer modeling proves our social distancing is having a postive effect.
