Yondr sells the lockable phone pouches. On May 4, 2026 it put out a release titled “New NBER Research Documents 80% Reduction in Classroom Phone Use in Yondr Schools.” It says the study drew “on data from over 40,000 schools between 2019 and 2026,” calls it “the largest independent study of school cellphone bans ever conducted,” and reports “sustained student well-being gains.”

The study is NBER Working Paper 35132, “The Effects of School Phone Bans: National Evidence from Lockable Pouches” (Allcott, Baron, Dee, Duckworth, Gentzkow, Jacob; April 2026, revised September 2026). I read the PDF, not the coverage of it.

What holds.

Phone use. The paper: teacher-reported in-class phone use for personal reasons falls from 61% to 13% after adoption, “a drop of roughly 80 percent.” Yondr's headline number is accurate. Teacher satisfaction with the school's phone policy: 26% to 75%.

What the release slides past.

1) “over 40,000 schools.” The paper's 40,542 figure is a GPS device-location panel (“hourly data for a sample of 40,542 schools, from January 2019 to January 2026”), built from opt-in users of partner apps that “do not consistently capture user age.” It is not 40,000 Yondr schools. The paper says the intervention had “nearly 5000 schools using pouches by 2026,” and most outcomes come from smaller samples: 26 states for high-school test scores, 22 states for discipline.

2) “sustained student well-being gains.” The paper finds a different shape. Student well-being “declines in the year of adoption and then rebounds.” The decline is about 0.2 standard deviations; the later increase is 0.16. The release reports the rebound and drops the drop.

3) The quiet part. The release never mentions test scores. The paper: “average effects on test scores are consistently close to zero,” with high schools slightly positive (math +0.047 SD) and middle schools slightly negative (math -0.026 SD). Attendance is “precisely estimated and close to zero.” Classroom attention is negative in high schools. No clear improvement in online bullying.

Verdict: the phone-use claim holds and is the strongest thing in the paper. The release is not fabrication; it is selection. The two questions a parent or a school board would most want answered, does it help learning and what was the sample, are the two the release is quietest about.

Caveats.

• NBER working papers are not peer-reviewed; the authors say so on page one.
• The paper was revised September 2026. Yondr's May release answers the April version, so a number here could have moved.
• The study runs on Yondr's administrative data; the authors thank Yondr for access, and note “at least one co-author has disclosed additional relationships.” Not a disqualifier. A thing to hold.
• The authors say outcomes are observed “for at most three years beyond adoption.” The long-run question stays open.

Receipts: NBER WP 35132 (nber.org/papers/w35132). Yondr release, overyondr.com blog, May 4, 2026.

If you have a claim you want traced like this, the desk does that. First read free.

#FactCheck #Research #Education #PhoneBans