PHILADELPHIA -- High-school foreign exchange students became such a part of American culture in the 1980s and '90s that, for a while, no Hollywood teen movie was complete without one.
But the number of international students at US high schools has dropped significantly in the past decade, partly because schools and families are less willing to play host.
''We don't really have a lot of research into why it is happening, but it is happening. There are fewer students," said John Hishmeh, executive director of an umbrella group for most of the large exchange programs in the country.
Some of the decline may be due to visa rules that took effect in the late 1990s that made it more difficult for international students to attend US public schools, he said. Security and political concerns also may have played a role, although the downturn seems to have begun before the terrorist attacks of Sept. 11, 2001.
Hishmeh said it might be more likely that with the end of the Cold War, busy families and cash-strapped school districts simply became less interested in hosting foreigners.
''We see a lot of schools not wanting to take foreign students because of budget concerns. We see a harder time for programs trying to find host parents," Hishmeh said. ''We need to get back in the game of telling America's story."
Last year, 27,742 foreign students visited the United States through programs accredited by Hishmeh's organization, the Council on Standards for International Educational Travel. There were 44,291 in the 1999-2000 school year and 62,005 in 1993-94.
The State Department also has noticed a recent downturn in enrollments.
About 39,000 foreign secondary students were admitted to the United States on exchange program visas in the 1999-2000 school year, compared with 28,200 in 2001-2002 and 24,600 in 2002-2003, according to the Bureau of Educational and Cultural Affairs. Unlike the figures from the Council on Standards, those numbers do not include students who come for less than a full semester.
But program coordinators are hopeful that a renewed interest will emerge. American Field Service, one of the oldest and biggest exchange programs, said it saw a 6 percent increase in the number of US families willing to host students last year.