prah's Book Club may help sell millions of books to Americans, and slam poetry may have engendered a youthful new breed of wordsmith, but the nation is still caught in a tide of indifference when it comes to literature. That is the sobering profile of a new survey to be released today by the National Endowment for the Arts, which describes a precipitous downward trend in book consumption by Americans and a particular decline in the reading of fiction, poetry and drama.

The survey, called "Reading at Risk," is based on data from "The Survey of Public Participation in the Arts," conducted by the Census Bureau in 2002. Among its findings are that fewer than half of Americans over 18 now read novels, short stories, plays or poetry; that the consumer pool for books of all kinds has diminished; and that the pace at which the nation is losing readers, especially young readers, is quickening. In addition it finds that the downward trend holds in virtually all demographic areas.

"What this study does is give us accurate numbers that support our worst fears about American reading," said Dana Gioia, the chairman of the endowment, who will preside over a discussion of the survey results at the New York Public Library this morning. "It quantifies what people have been observing anecdotally, but the news is that it has been happening more rapidly and more pervasively than anyone thought possible. Reading is in decline among all groups, in every region, at every educational level and within every ethnic group," he said, calling the survey results "deeply alarming."

The study, with its stark depiction of how Americans now entertain, inform and educate themselves, does seem likely to fuel debate over issues like the teaching and encouragement of reading in schools, the financing of literacy programs and the prevalence in American life of television and the other electronic media that have been increasingly stealing time from readers for a couple of generations at least. It also raises questions about the role of literature in the contemporary world.

The survey also makes a striking correlation between readers of literature and those who are socially engaged, noting that readers are far more likely than nonreaders to do volunteer and charity work and go to art museums, performing arts events and ballgames. "Whatever good things the new electronic media bring, they also seem to be creating a decline in cultural and civic participation," Mr. Gioia said. "Of literary readers, 43 percent perform charity work; only 17 percent of nonreaders do. That's not a subtle difference."

Still, in a world where information is more readily available than ever, where people know more than they ever have, and where visual acuity is becoming ever more crucially utilitarian, it is worth asking: What, if anything, does literature's diminished importance to Americans represent? The study has already produced conflicting reactions.

"It's not just unfortunate, it's real cause for concern," said James Shapiro, a professor of English at Columbia University. "A culture gets what it pays for, and if we think democracy depends on people who read, write, think and reflect ó which is what literature advances ó then we have to invest in what it takes to promote that."

On the other hand Kevin Starr, librarian emeritus for the state of California and a professor of history at the University of Southern California, said that if close to 50 percent of Americans are reading literature, "that's not bad, actually."

"In an age where there's no canon, where there are so many other forms of information, and where we're returning to medieval-like oral culture based on television," he said, "I think that's pretty impressive, quite frankly." Mr. Starr continued: "We should be alarmed, I suppose, but the horse has long since run out of the barn. There are two distinct cultures that have evolved, and by far the smaller is the one that's tied up with book and high culture. You can get through American life and be very successful without anybody ever asking you whether Shylock is an anti-Semitic character or whether `Death in Venice' is better than `The Magic Mountain.' "

The Census Bureau study upon which the survey was based measured the number of adult Americans who attended live performances of theater, music, dance and other arts; visited museums; watched broadcasts of arts programs; or read literature in the past year. The survey sample ó 17,135 people ó makes it one of the largest studies ever conducted on the subject of arts participation, and the data were compared with similar studies from 1982 and 1992. In the literature segment respondents were asked whether they had, during the previous 12 months, without the impetus of a school or work assignment, read any novels, short stories, poems or plays in their leisure time.

Their answers show that just over half ó 56.6 percent ó read a book of any kind in the previous year, down from 60.9 percent a decade earlier. Readers of literature fell even more precipitously, to 46.7 percent of the adult population, down from 54 percent in 1992 and 56.9 percent in 1982, which means that in the last decade the erosion accelerated significantly. The literary reading public lost 5 percent of its girth between 1982 and 1992; another 14 percent dropped away in the following decade. And though the number of readers of literature is about the same now as it was in 1982 ó about 96 million people ó the American population as a whole has increased by almost 40 million.

The survey found that men (37.6 percent) were doing less literary reading than women (55.1 percent); that Hispanics (26.5 percent) were doing less than African-Americans (37.1 percent) and whites (51.4 percent); but that all categories were declining. The steepest declines of any demographic group are among the youngest adults. In 1982, 59.8 percent of 18-to-24-year-olds read literature; by 2002 that figure had dropped to 42.8 percent. In the 25-to-34 age group, the percentage of literary readers dropped to 47.7 from 62.1 over the same period.

"This won't be news to publishers," said Jim Milliott, senior editor for news at the trade journal Publishers Weekly. "It just confirms what we've known from other fragmented surveys all along."

Last month the Association of American Publishers released worldwide sales figures for 2003, indicating that total sales of consumer book products increased 6 percent for the year. Much of the increase can be accounted for by sales of audio books, juvenile titles and nonpaper e-books, sold online. Adult hardbound books, adult paperbacks and mass-market paperbacks all showed relatively flat revenues, in spite of price increases.

The one category of book to rise markedly was that of religious texts, with total sales of $337.9 million, 36.8 percent over the previous year.