Chile's Sistema de Admisión Escolar (SAE) demonstrates how research-driven technology can transform school choice systems at scale. Over ten years, this centralized platform has processed over 4.5 million applications while maintaining 90%+ assignment rates and generating measurable academic improvements. Academic research efforts parallel to implementation revealed powerful results: large academic gains through better matching, dramatic reductions in search costs for families, and narrowed equity gaps. Together, these achievements have established a transparent and sustainable system for the government to build on for years to come.

Since scaling from 63 schools to nearly 8,000, SAE is one of the largest school choice coordination efforts in the world. The system's evolution—in part enabled by Professor Christopher Neilson's market design research and later scaled through Tether Education (founded by Professor Neilson)—offers actionable insights for governments and districts seeking to modernize enrollment processes and improve educational equity.

Prior to 2016, Chile's school admissions operated under a fragmented, decentralized system. This system created multiple market failures that particularly disadvantaged lower-income families and perpetuated educational inequality.

• Large search costs: Decentralization forced families to navigate the system alone. Research found that in indirect costs (e.g., transportation, time lost on mandatory school visits), families were spending $10 per child under the old system. Similarly, schools were spending $13.60 per applicant on administrative burdens.
• Misinformed families: Parents only knew 1 in 5 nearby schools, and they didn’t know about many nearby, high-quality schools. Parents also heavily underestimated the number of nearby schools that were free. (In Chile, private K-12 options are prevalent.)
• Opaque processes: Decentralized systems allowed schools to retain broad discretion in admissions. The lack of transparency raised concerns of favoritism, illegal screening based on academic and socioeconomic characteristics, and even informal quid-pro-quo agreements.
• Capacity underutilization: Perhaps most significantly, the lack of coordination led to 4 in 5 schools starting the year with 10% empty seats. Students lost out on precious learning time, while schools faced uncertain funding conditions.

The decentralized system caused acute and system-wide issues. Without alignment in data and process across schools, the government could not address any of them, and often could not quantify the problem. As educational achievement and access gaps became more apparent on the public stage, policy makers started to focus on the decentralized system as an opportunity to upgrade Chilean education. Something had to change.

While reform had been percolating in the government for some time, the new system truly kicked off with the 2015 Inclusion Law, which mandated standardized admissions procedures to all publicly funded schools. Professor Neilson served as an advisor to Chile’s Ministry of Education throughout this transition. At the core of reform was a centralized application platform that used a strategy-proof matching algorithm to convert student applications into enrollments. Implementation would be staged across several years, but SAE had officially begun. 

Phase 1: System Design

Supported by advisors like Professor Neilson, the Ministry of Education successfully included several important platform features:

• Dynamic sibling priority: Innovative “family applications” to increase likelihood of same-school assignment for siblings reduced burden for families, who previously had to strategize or navigate complex priority schemes to ensure desired enrollment.
• Process transparency: Legally mandated, publicly available criteria and outcome data eliminated discretionary admissions, enabled research, and created an informed public.
• All-inclusive platform: All publicly funded schools—including voucher-eligible private schools—had to operate through SAE, maximizing the system’s ability to eliminate public sector bias and inequity.

However, administrators acknowledged that efficient system design alone could not address all problems. A gradual rollout, accompanied by mechanisms to guide families through processes, promoted iterative improvement.

Phase 2: Phased pilots with behavioral interventions

The first pilot in 2016 included 63 schools in Southern Chile. Neilson helped launch a randomized controlled trial (RCT)—the gold standard for social science research, and just one of many associated with SAE—to study the effect of behavioral “nudges” to help students with “risky” applications avoid not getting into any of their choices. Results were significant but modest, pushing the team to improve further as SAE scaled throughout the country.

Phase 3: Smart platforms and the birth of TetherEd

The SAE team had strong (and global) evidence that faulty beliefs and lack of information impaired families’ abilities to navigate systems like SAE. They also had local, real-time data to uncover issues as they unfolded. Duly equipped, they launched two projects to promote coordination and ease navigation:

• Personalized school explorer: To reduce faulty search, the “Explorer” clearly displayed a family’s local education market in a standardized way, and customized recommendations based on proximity, quality, and admission odds introduced each family to new options.
  
  • Large scale RCT (280,000 families) results demonstrated that the Explorer improved knowledge of nearby, high-quality schools by nearly 25%, and resulting school matches improved test scores by 0.2 standard deviations for affected students
• Waitlist management: Recognizing that many students did not enroll through SAE’s first match (up to half of all new enrollments—a phenomenon common across the world), an official waitlist system to address this “aftermarket” was created. This waitlist system digitized a previously in-person, informal queue model, and it centralized the process of assigning empty seats.
  
  • The aftermarket consisted of students who moved, students moving from private schools, and students not satisfied with their first SAE match. Improving this process was critical to ensuring consistent, fair assignment and ensuring students could stay in the public system with quality educational options.

Over time, Neilson evolved from policy advisor and researcher to implementer. His nonprofit, ConsiliumBots, initially managed Chile’s nationwide algorithmic assignment and personalized feedback system as SAE expanded to nearly 8,000 publicly funded schools. Recognizing the growing need to scale these research-backed mechanisms, Neilson founded Tether Education in 2022. TetherEd contributes to SAE’s legacy by managing the waitlist and its 1.4 million applications annually. TetherEd’s robust product suite—including personalized feedback, transparent algorithm design, and dynamic waitlist management—builds directly on insights from SAE-related research. Like the SAE model, TetherEd remains closely embedded in ongoing research to stay at the forefront of innovation.

Thanks to integrated academic research, SAE (and TetherEd) can point to several improvements.

• Lower costs: Indirect family application costs dropped by almost 75%, from $10.00 to $2.81 per child, while administrative costs for schools fell by 99%, from $13.60 to $0.16 per applicant.
• More, easier enrollment: SAE has an automated match rate over 90%, outperforming many popular centralized systems (e.g., New York City, Boston) and ensuring the low family burden.
• Better informed families: Behavioral interventions, such as real-time non-assignment risk warnings and personalized school recommendations, decreased the likelihood of applicants remaining unassigned by 58% among high-risk families.
• Equity gains: Just-in-time information interventions, at full strength, could equalize school placement quality across socioeconomic status.
• Academic gains: Similarly, enhanced information and application support improved school placement quality to the tune of 0.2 standard deviations in fourth-grade math and reading scores.

What can other governments and districts learn from SAE? TetherEd can point to two main takeaways:

First, integrating technology, behavioral insights, and evidence-based iteration allows for a system embedded with internal evaluation and data-driven, student-centered policies. Compared to the decentralized system preceding SAE, Chile currently operates with reams of accessible information and agile, informed decision-making ability. This enables future coordination and is perhaps the government's most significant outcome.

Second, addressing the entire enrollment lifecycle, from first application to waitlist entry to relocation, both improves system efficiency and addresses the needs of often-overlooked students.

The lessons from Chile’s decade of school choice reform underscore the value of collaboration, data-driven design, and continuous learning. TetherEd is dedicated to partnering with education agencies, schools, and communities to advance transparent, equitable, and effective enrollment processes. To learn more about how research and practical tools can support your school system’s goals, please get in touch.