The number of international students in the U.S. fell by 2.2 percent at the undergraduate level and 5.5 percent at the graduate level from fall 2016 to 2017, according to a new report from the National Science Foundation, “Science and Engineering Indicators,” released last week.

The analysis is based on government-held student visa data and excludes students who are participating in optional practical training, a program that allows international students to stay and work in the U.S. for up to three years after graduating while remaining on their university's sponsorship.

2016 2017 Percent Change All Fields Undergraduate 450,850 440,720 -2.2% Graduate 389,310 367,920 -5.5% Science and Engineering Fields Undergraduate 176,570 176,930 0.2% Graduate 244,040 229,310 -6% Non-Science and Engineering Fields Undergraduate 274,280 263,790 -3.8% Graduate 145,270 138,610 -4.6%

The declines come on the heels of years of steady growth (see line graph below) in overall international enrollments at U.S. universities and amid widespread concern that prospective new students could be deterred by the current political climate and uncertainty about immigration policies in the United States.

The declines, if they were to continue, could have negative implications for U.S. competitiveness and the health of American graduate science and engineering programs, which are heavily populated by international students. In 2015, international students made up 36 percent of all science and engineering graduate students in the U.S. and received more than half of all doctoral degrees awarded in computer science, economics, engineering, and mathematics and statistics.

The student visa-sourced data provide the first comprehensive national picture of international enrollments for the current academic year. It differs from an annual report on international enrollment conducted by the Institute of International Education, called Open Doors, which surveys universities about their international enrollments and reports the data on a one-year lag.

In November, Open Doors reported a 3.3 percent decline in new (as opposed to total) international students in the 2016-17 academic year and an overall flattening of growth.

A companion "snapshot" survey IIE conducted in association with other academic groups asked about 500 institutions about their international enrollments for the current academic year. Over all, the universities in the survey reported an average decline in new international enrollments of 7 percent. But the declines weren't being felt across the board: while 45 percent of institutions responding to the snapshot survey reported declines in new international students, 31 percent reported increases and 24 percent reported no change.

Among the reasons university officials have given for the declines in international student enrollments are the political and social environment in the U.S., the high cost of U.S. higher education, visa denial and delays, increasing competition from other countries, and changes to other governments' scholarship programs, such as Saudi Arabia's.

Here are a few of the international enrollment-related highlights of the NSF report: