School districts selected for clean school bus funding by the Environmental Protection Agency between 2012 and 2017 saw more than 350,000 estimated additional student days of attendance, according to a recent report from online research journal Nature Sustainability.

“Attendance improvements were greatest when the oldest buses were replaced and for districts with high ridership on applicant buses,” the report stated. “Extrapolating our results nationwide, we expect that the replacement of all pre-2000 model year school buses would lead to more than 1.3 million additional student days of attendance per year.”

The increase at which older, higher-polluting buses are replaced therefore seems to have a positive impact on student attendance, the report found.

Of 2,816 EPA applicants that met inclusion criteria and had complete data, 383 were selected for funding. The report’s authors noted that they found no statistical differences when comparing district sizes, demographics, and socio-economic status between winning and losing districts.

The Cleaner School Bus Data

Information gathered for the report included:

• EPA funding applicant data from lotteries between 2012 and 2017, including selection status, number of replacement buses requested, buses and engines replaced or retrofitted, and engine model year of replaced engines.

• School district information from the U.S. Department of Education’s annual Local Education Agency Universe Survey Data.

• School district attendance data between 2012-2019 from each state’s education department.

Beneficial Impacts of Lottery Selection

“Our findings are noteworthy because the randomized allocation of funding by the EPA allows for causal interpretation of the impact of school districts switching to cleaner buses,” the report stated.

The impacts from cleaner school buses are meaningful, given links between school attendance and student achievement.

“Excessive school absenteeism has also been linked to substance use, grade retention, and school dropout, the latter of which can have economic and health consequences in adulthood,” the report indicated.

The report’s authors noted that the study was limited by the relatively small number of entrants chosen for funding. Further restriction of data came when the authors had to scrap plans to include 2018 funding data due the lottery’s disruption by the coronavirus pandemic in 2019.