Last year, 99,196 students in the city’s traditional public schools, or nearly 10 percent of students, were classified as being in temporary housing, according to data from the New York State Technical and Education Assistance Center for Homeless Students, known as NYS-TEACHS, which is funded by the State Education Department and administered by Advocates for Children, a nonprofit group. At the same time, 6,249 students, or roughly 7 percent, in city charter schools were in temporary housing.

The major cause of the disparity, most people agree, is the way charter schools admit students. By law, charter schools admit students by lottery, and most hold their lotteries in April. Many receive more applicants than they have seats available. So, if a family moves between April and September, or in the middle of the school year, and is looking for a school seat in a new neighborhood, they will often be unable to get one in a charter. District schools, in contrast, more easily allow children to move between them.

Charter enrollment “will always disadvantage kids in temporary housing,” Jennifer Pringle, the director of NYS-TEACHS, said. “You have a kid who’s placed in a shelter where the local traditional public school is co-located with a charter school,” she explained. “You can enroll midyear in the traditional public school, but you can’t enroll in that charter school if they don’t have available seats.”

Homeless students are also distributed unevenly among the city’s traditional public schools. There are schools with very few, or no, homeless students, and there are neighborhood elementary schools which, because of overcrowding, will not admit a student in the middle of the year.

However, in at least 21 of the 29 geographic school districts in the city that have charters, every charter had a lower percentage of students in temporary housing last year than the average among the traditional public schools in the same district. In District 9 in the Bronx, for example, which had the highest concentration of students in temporary housing, 23 percent of students in the traditional public schools were in temporary housing last year, according to data from NYS-TEACHS. Most charters there had percentages of homeless students in the single digits. Icahn Charter School 6 and South Bronx Classical Charter III had the highest percentage, 12 percent.