The point of view is a third-person one. The narrator relates Paul's story more effectively than if it had been told through Paul, for example. Because the narrator is objective, we get a thorough picture of what Paul's life is like and what he is going through. This is why the narrator's account moves the plot along well.
The only character that the narrator develops is Paul because that is the only character that needs development. It is important we know his father's role and others' roles in Paul's decision to steal from his employer and go, on a whim, to New York City to fulfill a little of his dream. The other characters are flat because they do not need development. If there were developed, it would shift the focus away from Paul.
The point of view helps shape the theme through the straight forward style of the narrator. We learn quickly about the troubles that Paul is facing and how he can be irrational when dealing with these problems when pushed far enough.