Question: Joyce Carol Oates and Arthur Koestler, share which mutual industry occupation?
Context: Joyce Carol Oates (born June 16, 1938) is an American writer.  Oates published her first book in 1963 and has since published over 40 novels, as well as a number of plays and novellas, and many volumes of short stories, poetry, and nonfiction.  She has won many awards for her writing, including the National Book Award, for her novel "them" (1969), two O. Henry Awards, and the National Humanities Medal.  Her novels "Black Water" (1992), "What I Lived For" (1994), "Blonde" (2000), and short story collections "The Wheel of Love" (1970) and "Lovely, Dark, Deep: Stories" (2014) were each finalists for the Pulitzer Prize. The Gravedigger's Daughter is a 2007 novel by Joyce Carol Oates.  It is her 36th published novel.  The novel was based on the life of Oates's grandmother, whose father, a gravedigger settled in rural America, injured his wife, threatened his daughter, and then committed suicide.  Oates explained that she decided to write about her family only after her parents died (in 2000 and 2003), adding that her "family history was filled with pockets of silence.  I had to do a lot of imagining." First Love: A Gothic Tale is a novella by award-winning novelist and essayist Joyce Carol Oates and illustrator Barry Moser.  It tells the story of Joise S_____, a girl who goes to stay at her aunt's mansion in upstate New York.  While there, she has an incestuous relationship with her cousin, Jared.  The novella deals with two of the more common recurring themes in Oates' work: "teenage initiation and perplexing and problematic love." Living with Koestler: Mamaine Koestler's Letters 1945–51 is a book about the author Arthur Koestler and Mamaine Paget, Koestler’s second wife.  More specifically, it is a selected compilation of Mamaine’s letters to her twin sister Celia about her life with Koestler.  The spontaneous and engaging letters reflect the intensity of her life with Koestler between 1945 and 1951. Bellefleur (1980) is a magic realist novel by Joyce Carol Oates about the generations of an upstate New York family.  It is the first book in Oates' "Gothic Saga" and at the time of publication represented a major departure from the modern-day themes about which Oates had written up to that point. Blonde is a bestselling 2000 historical novel by Joyce Carol Oates that chronicles the inner life of Marilyn Monroe, though Oates insists that the novel is a work of fiction that should not be regarded as a biography.  It was a finalist of the Pulitzer Prize (2001) and the National Book Award (2000). " Rocky Mountain News" and "Entertainment Weekly" have listed "Blonde" as one of Joyce Carol Oates's best books, and Oates herself has said that "Blonde" is one of the two books (along with 1969's "them") for which she thinks she will be remembered. Arthur Koestler: The Story of a Friendship is a book by George Mikes published in 1983, soon after Arthur Koestler’s suicide.  As the author states in the Introduction, the book is not a biography of the subject but a series of recollections and anecdotes of a friendship spanning more than thirty years from 1952 up to the time of Koestler’s suicide in March 1983. Arthur Koestler, ( ; ] ; Hungarian: "Kösztler Artúr" ; 5 September 1905 – 1 March 1983) was a Hungarian-British author and journalist.  Koestler was born in Budapest and, apart from his early school years, was educated in Austria.  In 1931 Koestler joined the Communist Party of Germany until, disillusioned by Stalinism, he resigned in 1938.  In 1940 he published his novel "Darkness at Noon", an anti-totalitarian work that gained him international fame.  Over the next 43 years, from his residence in Britain, Koestler espoused many political causes, and wrote novels, memoirs, biographies and numerous essays.  In 1968 he was awarded the Sonning Prize "for [his] outstanding contribution to European culture" and in 1972 he was made a Commander of the Order of the British Empire (CBE).  In 1976 he was diagnosed with Parkinson's disease and in 1979 with terminal leukaemia.  In 1983 he and his wife committed suicide at their home in London. The Corn Maiden and Other Nightmares is a collection of short stories and novellas by Joyce Carol Oates.  Published in 2011 by Mysterious Press, it contains several works that Oates had worked on over a period of fifteen years. "Arthur Koestler" is a book by Mark Levene published in 1984, a year after Arthur Koestler's suicide.  The book is divided into seven main chapters, of which the first of is a biography and the other six critical essays on each of Koestler's six novels, his stories and his play "Twilight Bar".
Answer: writer