Question: Which English writer won more Costa Book Awards, Kate Atkinson or J. B. Priestley?

Context articles: Day (Kennedy novel)
Avril Joy
J. B. Priestley
What Was Lost
When Will There Be Good News?
A God in Ruins (novel)
New Zealand Post Book Awards
Kate Atkinson
Costa Book Awards
Christie Watson

Day is a novel by A. L. Kennedy.
 It won the novel category and the overall Costa Book of the Year Award in the 2007 Costa Book Awards.
 The novel is about a man who was a tailgunner in a Lancaster bomber aircraft during World War II.
 Later, he is an extra in a film about prisoners of war.
Avril M. Joy is a British author whose short story "Millie and Bird" won the Costa Short Story Award in the 2012 Costa Book Awards.
John Boynton "J. B." Priestley, OM ( ; 13 September 1894 – 14 August 1984), was an English novelist, playwright, scriptwriter, social commentator and broadcaster.
What Was Lost is the 2007 début novel by Catherine O'Flynn.
 The novel is about a girl who goes missing in a shopping centre in 1984, and the people who try to discover what happened to her twenty years later.
 "What Was Lost" won the First Novel Award at the 2007 Costa Book Awards, and was short-listed for the overall Costa Book of the Year Award.
When Will There Be Good News?
 is a 2008 crime novel by Kate Atkinson and won the 2009 'Richard & Judy Best Read of the Year' at the British Book Awards.
 It is the third to involve retired private detective Jackson Brodie and is set in and around Edinburgh.
 It begins though in Devon where six-year-old Joanna witnesses the brutal murder of her mother, sister and brother and barely escapes with her own life.
A God in Ruins the ninth novel by Kate Atkinson was published in 2015.
 The main character, Teddy Todd is the younger brother of Ursula Todd, the protagonist in Atkinson's 2013 novel, Life After Life.
 Atkinson calls it the "companion piece" rather than a sequel to the earlier novel.
 Both books are about World War II.
 It won the Costa Book Award for Novel in 2015.
The Ockham New Zealand Book Awards are a series of literary awards to works of New Zealand citizens.
 They were created in 1996, merging the Montana Book Awards and the New Zealand Book Awards into the Montana New Zealand Book Awards.
 From 2010 until 2014, the awards were known as the New Zealand Post Book Awards.
 They are governed by the New Zealand Book Awards Trust.
Kate Atkinson, MBE (born 20 December 1951) is an award-winning English writer.
 She won the Whitbread Book of the Year prize in 1995 and, under its new name the Costa Book Awards, in 2013 and 2015 in the Novels category.
The Costa Book Awards are a set of annual literary awards recognising English-language books by writers based in Britain and Ireland.
 They were inaugurated for 1971 publications and known as the Whitbread Book Awards until 2006 when Costa Coffee, a subsidiary of Whitbread, took over sponsorship.
 The companion Costa Short Story Award was established in 2012.
Christie Watson (born 1976) is a British novelist whose novel "Tiny Sunbirds Far Away" won the Costa First Novel Award in the 2011 Costa Book Awards.
 Her second novel "Where Women Are Kings" also won critical praise and has been widely translated.