A new study by Stanford University researchers found that the typical charter public school student made learning gains equivalent to about two additional months of learning compared to their demographically similar peers in conventional public schools. These results are no doubt impressive, but they are even more remarkable considering that charter public schools spend almost 25 percent less per pupil than schools run by school districts.
According to data from the Center for Educational Performance and Information, charters in Michigan spent about $10,300 per student in 2010-2011 (the latest data available). That same year, conventional public schools spent about $12,800 per student, or 24 percent more than charters.
The return on investment for taxpayers from charter schools is substantially greater on average than that of conventional schools. For 12 months of learning, conventional schools spend about $1,067 per month per student. Charters, meanwhile, managed to produce 14 months of learning over in that same period, spending about $736 per month per student. The ROI for charter schools is about 45 percent better than conventional public schools.
Not only do charter schools in Michigan tend to produce a better result for students enrolled in them compared to their state-assigned school, they also produce a significantly better “bang for the buck” for taxpayers.
 Neither of these figures includes any money spent directly by intermediate school districts.