Here it is: “Can Male Authors Publish Books Under Female Names?”
Well, of course they can, but the real question is little better. “I’ve recently heard some sharp comments from friends about male authors publishing books under female names. The pseudonyms are sometimes gender-neutral, but in genres dominated by women, readers assume that these writers are women too,” blathers “Name Withheld.” ” I know there are historical examples of the inverse: female writers using male names or gender-neutral names that are assumed to be male. But are these equivalent? Whatever difficulty male authors may face in majority-female literary genres today cannot compare to women’s historical struggle to live a public life. Is it unethical for these male authors to present themselves this way?”
The clear answer is “You’re an idiot.” Oh, The Ethicist provides some prolix academic patter, but the fact that anyone could ask such a question shows just how group identity-obsessed so many people have become, particularly those inclined to read the New York Times. A book is worth reading or not by virtue of its quality, not the gender, color, ethnicity, religion, height, weight, political affiliation or favorite hockey team of the writer. The theory that a writer’s identity is crucial to the value of his or her art is a bastard offspring of the warped belief in the performing arts that, oh, just to pick a wild hypothetical out of the air, only an actress of Hispanic roots can play Maria in “West Side Story” (but casting that same actress as Snow White is fine and dandy). If an Irish Catholic female novelist produces a brilliant novel told from the viewpoint of a black farmer in Jim Crow Alabama and writes under the pen name of J’maal Washington just for giggles, no one should care.
Many will care, of course. That will not mean that the novelist did anything wrong.
Ethics Alarms 
No, it shouldn’t. This whole idea of cultural appropriation has made us all poorer culturally and intellectually.
There have been plenty of writers, including female writers, who have used pseudonyms, some of which have implied genders or ethnicities they didn’t have. There are many reasons why this has been done. If the work is good, it shouldn’t make a difference. If it’s bad, well…at least the writer’s real identity is hidden!
I really enjoyed writing serious fiction from female characters’ point of view. Never had any complaints, but people don’t give very detailed reactions. Unfortunately.
I was recently intrigued to find books by a couple of well known (Donald Westlake was one) mystery writers who used a pseudonym to publish a science fiction book back in the late 50s. One can speculate no end on that, but certainly Science fiction’s status was not nearly as high back then.
I can also remember when I discovered that one of my favorite science fiction/fantasy authors — Andre Norton — was a woman. And a damn fine writer.
For romance novels, I can easily understand the reasoning for a man to publish with a female pseudonym. In a niche field, first impressions can be important.
Here is a better question: Is it ethical for a writer to continue publishing books after he (or she) has been dead for a couple decades? Yes, I’m looking at you, Tolkien.
Then there is Robert E. Howard, although to be fair many of the later Conan novels didn’t pretend to be associated with him other than using the character. L. Sprague de Camp certainly hit a gold mine in Howard’s attic, though.