If we are to believe the authors of a new book on Birthright Israel, the program that funds free trips to Israel for Diaspora youth, the nine-year-old initiative is measurably transforming the Jewish world, one young Jew at a time.

“Israel is the greatest classroom the Jewish people has at its disposal, and Birthright is succeeding in bringing it to life,” said professor Barry Chazan, who together with professor Leonard Saxe wrote the just-released “Ten Days of Birthright Israel: A Journey in Young Adult Identity.”

Chazan, a professor emeritus at the Hebrew University’s School of Education, has been the chief architect of Birthright’s curriculum, while Saxe, a professor of Jewish community research and social policy at Brandeis University, has been evaluating the program since its inception.

The findings presented in the book, a mix of experiential anecdotes, Saxe’s research and Chazan’s pedagogic insights, are unequivocal.

The proof, as they say, is in the pudding. Saxe’s research compares participants with nonparticipants who had applied for a trip but been placed on a waiting list. The two groups, Saxe explains, are “the same in every measurable background characteristic,” and were similarly inclined to go on Birthright.

The results are clear. Connection to Israel “very much” or “to a great extent” rose in one surveyed group from 45 percent for nonparticipants to 61 percent for participants, and in another from 43 percent to 71 percent. Asked about their connection to the Jewish people, participants similarly led nonparticipants by about 10 percentage points.

Participants were also far more likely to see Israel as a “lively democratic society,” with those saying they “strongly agree” rising from 28 percent to 41 percent in one group.

Perhaps most impressively, 62 percent of participants “strongly agreed” that Israel was a “source of pride,” compared to 50 percent of nonparticipants, while 17 percent saw their future home in Israel, up from 12 percent among nonparticipants.

The program is even inspiring other ethnic and religious groups: It is being studied by Armenians, Irish Americans and even Palestinians as a model for strengthening diaspora identities.

The success in changing attitudes is multiplied by a massive growth in the scope of the program. Before Birthright, each year saw just 1,500 Jewish youth of Birthright age (18-26) visiting Israel for the first time. In 2000, Birthright’s first year, 10,000 came on the program. In 2008, 42,000 participants are to make the journey — a significant portion of the estimated 100,000 diaspora youth who reach Birthright-eligible age each year.

“We’ve made [visiting Israel] a basic component of the Jewish lifecycle, just like a brit [milah] or a bat mitzvah,” said Gidi Mark, the program’s director of marketing. “Now it’s not just about strengthening Jewish identity, but it’s becoming part of Jewish identity.”

The program is doing similar work among Israelis, Saxe and Chazan noted.

“The same identity issue exists for most Israelis,” Saxe said. “They’re Israeli, but not necessarily Jewish. We know from the Israeli participants themselves that they come away from this program with a feeling that they belong to the Jewish people. They express it in those terms.”

More than 30,000 Israelis have participated in Birthright thus far, mostly soldiers who join the tour buses for five days.

IDF behavioral researchers have found that this participation has a dramatic effect on the soldiers, who become more motivated in their military service and express greater desire to remain in Israel in their adult lives.

For Mark, one of its greatest gifts is the strengthened sense of confidence participants report after going home.

“Even if they don’t learn everything in 10 days,” he said, “they can still go back to anti-Zionists on their campuses and say to them, ‘Don’t tell me what you saw on CNN — I was there.'”

“Ten Days of Birthright Israel:

A Journey in Young Adult Identity” by Leonard Saxe and Barry Chazan (256 pages, Brandeis University Press, $24.95)