Should I let my nephew quit going to high school?

My sister's in jail so I'm like his dad/big brother. He's got a job at the warehouse I worked at for awhile when I was younger and wants to keep doing it rather than go back to school in the fall for his last year. I'm like his roll model but he picks up my bad habits too, I'm a pretty chill dude, but barely graduated high school, drink and smoke a lot, use a lot of profanity and on and on. I sell cars now and live in a trailer park. He's like a younger version of me (I'm 26 so not a huge age difference) .. he could make some pretty good cash at the warehouse and I'm not sure if it matters as long as gets his GED. What say you?