Okay kiddo, let me explain population impact measure to you in a way you'll understand.
Population impact measure is a way of measuring how much something affects a lot of people. So, let's say there's a new rule in school that all students have to wear hats. If we want to know how much this affects the whole school, we would use population impact measure.
To do this, we would count how many students are in the school, and then we would count how many students would have to change what they wear to school because of this new rule. If only a few students have to change, then the population impact measure would be low. But if lots and lots of students have to change, then the population impact measure would be high.
Population impact measure is really useful because it helps us understand how much something will affect lots of people. It can help people make decisions about whether or not to do something, and it can help us figure out how to make changes that will have the biggest impact on large groups of people.