One study two years ago observed a relationship between vaping and the LIKELIHOOD of starting smoking.  To achieve that relationship, it had to count every answer except "definitely not" (i.e., Yes, Maybe Yes, Probably Not) as affirmation that the teen would go on to smoke.  Really scientific!  There have been several longish-term studies showing that the percentage of adolescents who start by vaping and go on to smoking tobacco is less than 1%.  It makes no sense -- who would go from something that tastes good and is relatively cheap to something dirty, smelly and ridiculously expensive?  Give adolescents credit for some sense!