Why does Gary D. Schmidt write in second person in Okay for Now?

When writing in second person, the author has the narrator refer to the protagonist by the second-person pronoun you. Doing so can make it seem that the narrator is scolding the protagonist or the protagonist is doing some self-reflecting. Second-person narration is actually the rarest point of view to find in stories because it's very difficult to use effectively. Ohio University gives us the following example of second-person narration:

You missed the bus again because you just couldn't convince yourself to get out of bed. The comforter made a cozy nest around you, and there was the cat, a warm ball of fur curled next to you. So you had to walk all the way to work. ("Point of View and Narrative Voice")

Gary Schmidt actually uses Doug Swieteck, the story's protagonist, as his first-person narrator throughout Okay for Now. In contrast to second person, first person is created when an author uses first-person pronouns such as I and me. We can tell the story is written in fist person from the perspective of the protagonist by looking at the very first few sentences of the story:

Joe Pepitone once gave me his New York Yankees baseball cap.
I'm not lying.
He gave it to me. To me, Doug Swieteck. To me. (p. 7)

However, what is fascinating is that, all the way through, Doug tells the story to his reader as if he was speaking to a listening audience. In doing so, he occasionally tells his audience he has chosen to withhold certain information, such as details of Principal Peatie's insults. Also, he occasionally invites the audience into the story by addressing the audience in second person in such a way that he makes the audience share his same feelings. One example is seen in the first chapter when Doug relays a snide remark made by his father in reply to a legitimate concern expressed by his mother about their moving to a different town:

My father looked up from his two fried eggs. "How are we going to let Lucas know where we've gone? The U.S. Postal Service," he said in that kind of voice that makes you feel like you are the dope of the world. (p. 11)

In reality, it's Doug and his mother who are being made to feel stupid; however, in using the second-person pronoun you, Doug is making his reader feel what he and his mother feel by inviting the reader into the story.