Slightly more than half the schools and two-thirds of the students are in large cities, with a skewing toward the Northeast that modifies the national averages. “In New York, Chicago, Boston and Philadelphia, black and Hispanic students are underrepresented . . . while white and Asian students are significantly overrepresented,” write Finn and Hockett. These high schools may act “as a kind of refuge from . . . less desirable schools” for many white and Asian students.

Academically, the select schools have two great advantages. First, they can create a climate that favors success. Peer pressure encourages it. Students aren’t disparaged for doing well in class. Second, these schools can attract superior teachers. Finn and Hockett found that 11 percent of teachers have doctorate degrees, while only 2 percent in all high schools do, and 66 percent have master’s degrees, while 46 percent overall do. About a quarter of the teachers have backgrounds in business, government, technology or the military.

The study’s great gap involves outcomes. Finn and Hockett couldn’t find or assemble data on how well these students do and whether they might have done as well in regular high schools. Though strong, the case for more select high schools is not a slam-dunk. As Finn and Hockett note, creating more such schools will spawn opposition and objections. Principals, teachers and PTAs of existing schools “will be loath to lose able pupils and education-minded parents.” Their loss will lessen pressure to “offer more advanced courses” at existing schools.