There is a (possible) issue on chapter 1, in the following paragraph
Now, let's add and subtract . This is a counterfactual outcome. It tells what would have been the outcome of the treated, had they not received the treatment.
It could be:
Now, let's add and subtract (as this makes no mathematical difference and allows us to rearrange later). This is a counterfactual outcome. It tells what would have been the outcome of the treated, had they not received the treatment.
There is a (possible) issue on chapter 1, in the following paragraph
Now, let's add and subtract. This is a counterfactual outcome. It tells what would have been the outcome of the treated, had they not received the treatment.
It could be:
Now, let's add and subtract (as this makes no mathematical difference and allows us to rearrange later). This is a counterfactual outcome. It tells what would have been the outcome of the treated, had they not received the treatment.