The most obvious parallel between these two characters is that like Christopher, Franklin also runs away to join the wilderness. Christopher harbours a deep centered resentment for his parents and by extension all authority. He seeks the freedom to live how he chooses and so seeks the refuge of the wilderness, free from the constraints of society, to live how he sees fit. Franklin also has negative feelings for his parents as both of them are substance abusers, and he himself is an alcoholic in secret. Franklin runs away for the same reasons that Christopher does, to isolate himself from a society that he feels oppressed by. Therefore, a second parallel are the reasons for which they choose to abandon society for a life of isolation.
Unlike Christopher who dies in the end, however, we see Franklin learn at the end of the novel that the best way to solve one's problems is to face them head on, not run away.