Whose story is it? I'm not asking who the main character is, but who is the center of the tale? Who is the tale mostly based on? I am deciding between Jem and Scout.
I'd have to say it is Scout's story. This is in part because it is her narrative; we hear things from her point of view. But beyond that, while Jem grows and matures, it is Scout who undergoes the greatest transformation, morally, socially, and within her family and community.