The number of doctoral degrees awarded by American universities climbed by 5.1 percent in 2006, to a record high of 45,596, according to a report released Tuesday by the National Science Foundation.

Those who have sounded the alarm about the country's perceived underproduction of skilled scientists and engineers may be heartened by the fact that almost all of the overall increase -- 1,865 of the 2,211 more doctorates awarded in 2006 than 2005 -- came in science and engineering fields.

But 1,521 more doctorates were granted in 2006 than in 2005 to scholars who are not U.S. citizens, more than two-thirds of all of the new Ph.D.'s and other terminal degrees awarded. In total, foreign born researchers accounted for nearly 35 percent of all doctorates granted in 2006 (15,947 of 45,596), and for 43 percent of the Ph.D.'s awarded in scientific and engineering fields (12,775 of 29,854). Non-citizens accounted for more than 70 percent of doctorate recipients in electrical, civil and industrial/mechanical engineering, and more than half of Ph.D. recipients in all other engineering fields, computer sciences, math and physics.

The data, which provide the first look at the production of doctorates in the 2005-6 academic year, come from the Survey of Earned Doctorates, an annual study sponsored by six federal agencies: the U.S. Departments of Education and Agriculture, the National Aeronautics and Space Administration, the National Endowment for the Humanities, the National Institutes of Health, and the NSF.

The NSF data focus on Ph.D. production in the sciences, and provide significantly less detail about non-science fields -- detailed information about the breakdowns in humanities and social science disciplines are available in the full report of the Survey of Earned Doctorates, which the University of Chicago's National Opinion Research Council, which conducts the survey, posted on its Web site Wednesday.

As seen in the table below, the increase in doctorate production in the sciences was driven largely by growth in the biological sciences, chemistry, computer sciences, and electrical engineering, all of which experienced growth of at least 200 doctorates (mathematics and mechanical engineering also fared well). Psychology and agricultural sciences suffered small declines.

Outside the sciences, universities awarded about 3.5 percent more Ph.D.'s and other doctorates in the humanities in 2006 than in 2005, about 6.8 percent more in health fields, and about 6.4 percent more in professional or other fields. The number of doctorates awarded in education declined, to 6,124 from 6,226, but more doctorates were awarded in education than in any field other than the biological sciences.

Doctorates Awarded by American Universities, 2000-2006

Men and women shared almost equally in the increases in doctoral degrees awarded in science and engineering fields, as seen in the table below. And Hispanic Americans saw a slightly bigger proportional increase in their share of the new doctorates awarded than did any other racial group.

Ph.D. Recipients in Science and Engineering Fields 2002-6, by Gender and Race

Of the 15,947 doctorates awarded to non-U.S. citizens, 1,829 went to permanent residents of the United States and 14,118 to those in the country on temporary visas. The table below shows the representation of foreign-born scholars among the Ph.D. recipients in various fields in 2006: