“Competition is a sin” (Rockefeller?)

“Competition is (a) sin” is often credited to John D. Rockefeller (1839-1937), the founder of the Standard Oil Company. The saying has been attributed to Rockefeller since at least 1971, but there is insufficient evidence that Rockefeller said it.
   
 
Wikipedia: John D. Rockefeller
John Davison Rockefeller (July 8, 1839 – May 23, 1937) was an American oil magnate and philanthropist. He was the founder of the Standard Oil Company, which dominated the oil industry and was the first great U.S. business trust. Rockefeller revolutionized the petroleum industry and defined the structure of modern philanthropy. In 1870, he founded the Standard Oil Company and aggressively ran it until he officially retired in 1897. Standard Oil began as an Ohio partnership formed by John D. Rockefeller, his brother William Rockefeller, Henry Flagler, Jabez Bostwick, chemist Samuel Andrews, and a silent partner, Stephen V. Harkness. As kerosene and gasoline grew in importance, Rockefeller’s wealth soared, and he became the world’s richest man and first American worth more than a billion dollars. Adjusting for inflation, he is often regarded as the richest person in history.
 
Wikiquote:TalkJohn D. Rockefeller
Unsourced
Competition is a sin, therefore you must destroy it.
     
Google Books
David
By William Hoffman
New York, NY: Dell
1972, ©1971
Pg. 29:
Later, in Justifying his establishment of one of the most ruthless monopolies mankind has been forced to witness, John said simply, “Competition is a sin.”
 
Google Books
The Unseen Hand:
An introduction to the conspiratorial view of history

By A. Ralph Epperson
Tucson, AZ: Publius; Westlake Village, CA: Distributed by American Media
1985
Pg. 73:
John D. Rockefeller, one who correcdy assessed the situation as well, expressed the opinion that “Competition is a sin.”
Pg. 469:
THE ROCKEFELLER FILE, by Gary Allen
Starts with John D., (“Competition is a sin”);...
 
Google Books
The Shadows of Power:
The Council on Foreign Relations and the American decline

By James Perloff
Boston. MA: Western Islands
1988
Pg. 44:
In fact, Rockefeller once said: “Competition is a sin.”
 
Google Books
World without Cancer:
The story of vitamin B17

By G. Edward Griffin
Westlake Village, CA: American Media
1997
Pg. 229:
Once again,we must remind ourselves that, in spite of all the rhetoric to the contrary, monopoly is not the product of free-enterprise capitalism, but the escape from it. John D. Rockefeller himself had confirmed this many times in his career . One of his favorite expressions was “Competition is a sin.”

Google Books
The Book of Bastards:
101 Worst Scoundrels and Scandals from the World of Politics and Power

By Brian Thornton
Avon, MA: Adams Media
2010
Pg. ?:
“Competition is a sin.” — John D. Rockefeller