Disputing a common mantra of charter advocates that unions have an adverse effect on student learning, a new study has found that student achievement in fact rises when charter schools unionize.
Researchers Jordan D. Matsudaira of Cornell University and Richard W. Patterson of the U.S. Military Academy compared the change in test scores in California charter schools that unionized with the change in scores for non-unionized charter schools in the state after controlling for differences in student demographics and school characteristics.
In findings published in the Economics of Education Review, Matsudaira and Patterson concluded that student achievement in math rose substantially beginning in the year after the charter unionized and the gains continued in magnitude for at least two more years. The lowest-performing students improved the most. Scores rose in English language arts as well, though the increase was relatively small.
The researchers found that teachers in the unionized charter schools had about four more years of experience on average compared with their counterparts in non-unionized charters. About 80 percent of the teachers in unionized charter schools were tenured compared with only 30 percent at non-unionized charters, according to the study.
Charter schools enrolled close to one-third of California students in 2013. Of California’s 1,127 charter schools in existence that year, approximately a quarter were unionized.
The new findings dispute a research study published in 2015 that showed no distinguishable difference in student performance between unionized and non-unionized charters. That study combined the math and ELA scores into one result, a weaker research methodology, and thus didn’t detect the impact of unionization on student performance.
Matsudaira and Patterson speculated that improved student learning in unionized charter schools could reflect improved teacher morale or better relationships between teachers and school leadership in those schools. The authors noted that the impact of unions on student outcomes in charter schools will vary from school to school since contract provisions vary.