If hip hop does have an effect, it's negligible compared to everything else that young people are exposed to.
You might order some Grey Goose @ the bar cause you heard Jay Z talk about it, but even with a step by step booklet on how to sell hand to hand, it's not gonna happen. At best it puts an idea in your head, an idea that competes with parents, school, religion, Television, movies, books, friends...et cetera
And it goes the other way too. Dudes can yell all they want about 'revolution', but at best it hits the folks who want to hear it, and some folks who are ready to recieve, and they go pick up a book.
Unless cats trying to make a parallel with the US and rwanda, lol.