Books printed in the U.S. are on a list of goods Canada may counter-tariff in response to the U.S. trade war. But booksellers say that would have a big impact on the industry at home, including on Canadian authors.

Don Gorman, the publisher of Rocky Mountain Books in Victoria, said Canada exports between $40 and $50 million worth of books to the U.S. each year. He said if U.S. tariffs were to go ahead next week, publishers may have to raise their...