I suppose it depends on the purpose of the metric you are evaluating. If your goal is to find the percentage of people currently unemployed because they are loo

I suppose it depends on the purpose of the metric you are evaluating. If your goal is to find the percentage of people currently unemployed because they are looking for a job but unable to get one, then it does not make sense to include students or retirees that are not currently looking for work. Besides, I'm not sure it's accurate to claim "society must pay for students and retirees". Some students can pay for themselves (via loans) and some retirees can pay for themselves (via their own retirement savings).