Providing a service without any expectation of a payment or reward is plenty motivation for some students, but for others there is a drive for a form of return. Some schools decided to require students to voulenteer before they graduate, and that is both a great thing and a bad thing. The good that comes from this is a general lesson of "goodwill" or "helping your neighbor". You basically are showing that you are willing to provide your services without an automatic expectation of a reciprocating payment. General goodwill is a trait that, I feel, there is a slight disconnect between us teens and the elderly age demographic. They were willing to set aside there time for others and honestly that was a great thing for everyone. Now the best thing we do for others is just send them a text back or a simple greeting.
But there is also negatives to the forced "volunteer to graduate" tactic. You are basically shoving this idea down the throats of young adults and hoping that it might stick with them. There is no good in that. The only message you're getting through is that "I'm older then you, I know more then you, therefore you are going to do what I say". Why would that do any good? There is no need for that, in fact you are harming them more then helping with this process. They are just gonna purposely ignore your lesson and then do the exact opposite.
I think kids should voulenteer there time. Whatever time they have left from their other activities should go out to bettering our coumminty, but this shouldn't be forced or left up to the parents. This should be something they do out of their free will. There should be no extra rewards either, it should just be a student realizing that there is some good in helping others out out of the kindness of your heart.