Claire Harrison, mother of two and wife of an employe of the Canadian embassy, has written and sold eight books since 1979. In a business where quantity dictates incomes, she is having the time of her life. Harrison is a romance writer, one of hundreds of American women who have found money in love and are cashing in on the current boom in romantic fiction.

The Romance Writers of America held its third annual convention at the Mayflower last weekend, and some 550 authors and would-be authors met in serious working sessions with agents and publishers from New York and Canada who have seen that love and marriage means megabucks.

With steaming titles of passion and eternal promise, paperback romances accounted for nearly half of the paperback sales last year. Most of the books are written by women and most are read by women. Hence, suggested a number of writers at the convention, the derision they must endure within the publishing establishment.

"This is not a genre of trash," says Rita Clay Estrada, past president and cofounder of the RWA, who is accustomed to defending her craft. "Most of our authors have college degrees.

"It's escape," she says, likening romances to the adventure novels men enjoy. "Women are into reading the whys and wherefores in relationships. Men are more into action." Estrada, a mother of four who writes short, contemporary romances that have made the Walden paperback best seller list, says romance authors can make "anywhere from $5,000 to $105,000 a year," with $50,000 being near the average. "It's the only career where you can work at home with a family and not have the two conflict with each other," she says. "You can write in the morning and in the afternoon you're with the children."

It is not, however, easy work, says Harrison. "You have to get into the emotions of the people involved." And, she says, "all the contemporary issues in women's lives are being addressed in romances. They're really ways of telling how problems can be solved."

Kathleen Gilles Seidel, a PhD in English literature who taught at Northern Virginia Community College, wrote one novel before realizing that, at current hardback prices, "no one would buy it." She wanted people to read her books. She sold a romance, "The Same Last Name," which Harlequin published this year with a press run of 300,000 copies.

Romances, say the authors, are changing, reflecting contemporary life. The heroines now almost always have careers, and some have been over 40. Characters and plots are becoming more topical, although explicit sex is generally frowned upon. The story, after all, isn't about sex; it's about love and commitment. "If you don't believe happiness is possible within marriages, you can't write romances," says Seidel.

"Men can learn a lot in these books," says Rita Gallagher, Estrada's mother and an author of historical romances. "The macho image doesn't appeal these days. The hero is sensitive, intelligent. He's trying to become what she wants him to be." Kay Mussel, an associate professor at American University, who has studied the history of the romance novel, believes the current popularity is partly due to the changes women have gone through during the past two decades. "Romances change," she says, "but they also confirm some old verities people believe in. They are fantasies of attachment."

Romance Writers of America has about 2,000 members, and 75 associated bookstores, which set up autographing sessions for visiting authors. Since publishers are notorious penny pinchers when it comes to promoting books, the romance writers often do it themselves. They arrange their own tours and interviews, often staying at each other's homes in different cities while on tour and when doing research. They critique each other's work and call each other for advice.

The romance writers, whatever the public and the publishing industry thinks of them, are women, many of them married and with children, who have sat down behind typewriters and word processors and launched an enormous cottage industry that produced some half a billion dollars in sales last year.

They know some people are laughing at their work. But they also know that the publishing industry is beginning to take them seriously. Unlike most writers, a lot of them are laughing all the way to the bank.