X writting as Y

In this case it is men writing as women and women writing as men. I found 2 good example.

J.K. Rowling writing as Harry Potter, telling the story of this young boy who discovers that he is a magician, son of excelent wizards. He is a legend also, for surviving to the attack of Voldemort (an evil magician) being just a baby.

Charles Dicken writing as Esther Summerson in "Bleak House". She tells the story of her involvement in the tortuous lawsuit of Jarndyce vs Jarndyce. The heartstrings are tugged when she tells us of losing her bloom after catching smallpox, but we know that her author will pair her up with the handsome young doctor.

The benefits of writing as an opposite sex, is that the author can express a very different perspective of how would a man or woman would react in some situation. Also there are some limitiation, because the author has never had the experience of being the other sex, so he doesn't has the escence and vibrations that women or men do have.

Some author may take another approach because of the message they want to express, also it is easier for them to express themselves.