The first time I read it, about ten years ago, I discussed the second-person narration with some people who had been assigned the book in college. Their view was that it is a powerful technique because it invites the reader to identify more closely than usual with the narrator. "You put yourself in the story," or something. That is just obviously wrong. It doesn't even make sense on its face-- the first person literally invites the reader into the mind of the narrator. You can't get closer to the narrator, or to the events of a story, than the first person.
The most familiar use of the second person, for those of us who grew up in the 80s, is the Choose Your Own Adventure series. In those books, the second person really is an invitation to readers to imagine these events happening to them. This works because the Choose Your Own Adventure books don't characterize their protagonists. The whole point is for kids to imagine themselves experiencing an adventure.
That is not the case with Bright Lights, Big City. McInerney's narrator is characterized in detail. I know what clothes he likes (and they aren't the same clothes I like). He spends most of the book seeking or snorting cocaine (and I've never tried cocaine). He's younger than I am, he's more emotionally frayed than I am, he works a job I've never had. I understand the ambivalence he feels toward Tad Allagash, even though I am not ambivalent: I loathe the guy.
So the narrator is not a blank on which I am supposed to project myself. And the choice of the second person is distancing, at least relative to the first or limited-third person. Why is it, in this case, so powerful?
Stacey Richter has a short story in the second person, "The Land of Pain," and it is excellent. It includes a digression about the second person that I think answers the question. Richter's story is about a woman suffering from chronic pain, who is raising a brainless clone of herself that, she hopes, will eventually provide her with a new, pain-free body.
You take your medicine and sack out in front of the television (which you can only really watch when you manage to nudge the pirouetting brainless clone into a corner). Now is the hour when citizens on talk shows tell their tragic stories in the second person, saying you you you about all the bad, traumatic, unfortunate experiences in their lives ("You just feel so betrayed when you see that little panda pulling a gun") as though they have a genetic defect that prevents them from using the pronoun "I." This is sloppy and angers the grammar and usage thug in you. You've concluded that citizens telling their tales of adversity find the second person compelling because "you" is impersonal and removed, yet somehow includes everyone in its scope ("It could be you staring down the barrel at that panda bear next, sweetheart!") whereas "I" is an orphaned baby doe blinking in a dark forest.Yes! The second person is powerful because it is impersonal and removed. It is a pattern of speech characteristic of people who are in the process of struggling (and as yet failing) to digest, to accept "all the bad, traumatic, unfortunate experiences in their lives." As I get deeper into Bright Lights, Big City, the choice of the second person starts to read less like youthful flamboyance from McInerney and more like a coping mechanism of the narrator's. Long before we start to understand just what bad, traumatic, unfortunate experiences have messed up our narrator, we start to develop the visceral, dreadful sense that he's in real pain. That's the second person in action.
"You are aways in pain," for example, is a more manageable utterance than the direct, final, "I am always in pain."
At nightfall, you can't find the assistive animal anywhere. Finally, you locate her curled up in the cage with the brainless clone, nose tucked under her tail. They adore each other. And you, you my friend, are filled with jealousy.
(Richter also helps explain why the second person is usually paired with the present tense. It's present pain, not remembered pain, that forces people into the shelter of you you you.)