One of the better examples of this is the very brief vignette "Those Who Don't". It deals with unfair racial distinctions and the irrational fear many people have of "a neighborhood of another color". These fears work both ways:
"Those who don't know any better come into our neighborhood scared. They think we're dangerous [...] All brown all around, we are safe. But watch us drive into a neighborhood of another color and our knees go shakity-shake and our car windows get rolled up tight [...] That is how it goes and goes." (28)Esperanza notices how every race seems to be afraid of every other, how they don't understand others and don't try to. She speaks of it as a cycle, because neither group tries to understand the other (if there were only two, which there aren't, but that's not the point), and this allows the fear to continue; she also seems to realize that there isn't any reason for this to continue. The vignette explains that the people who are afraid of Esperanza's neighborhood are "stupid people who are lost and got here by mistake", and while it's never said directly, the implication seems to be that the people in her own neighborhood who are afraid of others are being just as narrow-minded. If the book is indeed her gift to the people of Mango Street, her intention may be to open their minds to the fact that people of other races should not automatically be seen as dangerous.
Earlier, in the very first vignette, Esperanza speaks of a previous home and how, when she pointed it out to a passing nun from her school, the nun reacted with obvious distaste; this was because the flat looked even from the outside like an undesirable place, due to a lack of money. Later, in "A Rice Sandwich", Esperanza tells the story of the one occasion when she ate lunch in the canteen at school. The school's Sister Superior says that Esperanza doesn't live far enough away from the school to need to eat in the canteen, and then goes to the window and points out "a row of ugly three-flats, the ones even the raggedy men are ashamed to go into" (45) with the guess that Esperanza lives there. These events, and others in the book, indicate a general contempt for poverty exhibited by many secondary characters. Perhaps this is another issue Esperanza aims to change with her writings? It wouldn't be possible to eliminate the poverty itself, not with a book, but at least people will not automatically look down on those with less money.
And how can we be sure that Esperanza intends this book to help those still on Mango Street? By the way she describes her first encounter with this idea. It arises in "The Three Sisters", where one of the title characters speaks to Esperanza about her desire to leave:
"When you leave you must remember to come back for the others. A circle, understand? You will always be Esperanza. You will always be Mango Street. You can't erase what you know. You can't forget who you are." (105)If the book is indeed Esperanza's message for those she leaves behind, this is her clue to those who read it. By including the message given to her by the mysterious sister, she is effectively saying: No, I have not forgotten who I am. I have remembered Mango Street, and I will come back for the ones I left behind. This, along with the final vignette, cements the theory that The House on Mango Street is what she offers those who "cannot out".
Of course, we know that Esperanza is herself fictional and technically cannot write a book, but many books are written with clear indication that they are intended to be seen as the character's writings; third-person books sometimes do this too. It gives the reader more concrete ideas about events after the book. Perhaps Esperanza, like Alicia, attended university; perhaps she became the one who is beautiful and cruel, and her stories are meant to teach others to do the same. It's certainly a nice thought.