The Thomas B. Fordham Institute recently published a study claiming that charter schools do no fiscal harm to public schools, and may even lead to greater funding. Dr. Carol Burris, executive director of the Network for Public Schools, has visited public school districts that are in a deep financial hole because of the financial drain caused by the proliferation of charter schools. She read the Fordham study with care and concluded that it was misleading and inaccurate.

Her article was published on Valerie Strauss’s “The Answer Sheet,” along with a response by the author of the study, Mark Weber. Weber agreed with her main point: – That said, I agree that my report does not provide evidence that charter school growth does not harm school district’s fiscal health. That fact is that this report can’t answer that question. My hope, however, is that it does provide a framework for having a more informed discussion about the costs of charter schools on the entire K-12 system.

Her full post is here.

It begins like this:

A recent study published by the Thomas B. Fordham Institute, entitled Robbers or Victims: Charter Schools and District Finances, was rolled out with fanfare and sent to policymakers across the country.  When the Fordham Institute sent out its mass email, trumpeting its report, its subject line read: “New report finds charter schools pose no fiscal threat to local districts.” That subject line is a blatantly false and unsupported by their own deeply flawed study.

In the report and its public relations campaign, Fordham cynically attempts to razzle-dazzle the reader with misleading conclusions based on questionable data in hopes of convincing the public that charter schools do no financial harm to public schools. The Walton Foundation and The Fordham Foundation, the Fordham Institute’s related organization, funded the study. It is worth noting that The Fordham Foundation sponsors eleven charter schools in Ohio, for which it receives administrative fees.

The origins of the study, unacknowledged in the report, is author Mark Weber’s 2019 doctoral dissertation. Advocacy organizations are often accused of cherry-picking examples. With Robbers and Victims, Fordham cherry-picked a study on which to base its puffery. In a Fordham podcast and his blog, Weber, an elementary school music teacher who completed his doctoral studies at Rutgers University, reports that Fordham approached him to author their report after they read his dissertation, which is composed of three papers, the first of which is the basis of the Fordham report.

There are differences in substance between the dissertation and the report; however, these are not enough to substantively change results. Also, Robbers or Victims adds two more years of data (2016 and 2017). The research questions are re-phrased, some states were excluded, and several of Weber’s original cautions regarding the interpretation and limitations of his findings are either downplayed or dropped. Glossy bar graphs replace Weber’s tables.

In both the dissertation and the report, Weber attempts to show the association between charter growth and districts’ finances in revenue and spending—as charter schools expand. He found that in most cases in the states whose data he analyzed, revenue and expenditures either increased or stayed the same when the number of students attending charters located in the district went up.  In all cases, there is no evidence of causation, just correlation.

For those not familiar with the distinction, a correlation occurs when two observations follow the same trend line. It does not present evidence that one causes the other. The classic example is the correlation between ice cream sales and murder rates—both are higher during summer months in big cities and then drop as the weather gets cooler. Then, there are hilarious examples of Spurious Correlations that show the associations between such oddities as the age of Miss America and murders by steam, hot vapors, and hot objects.

Fordham’s Petrilli latches onto the correlation and concludes that it appears charters do no financial harm to districts. In their news brief about the report, the National Alliance of Charter School Authorizers take Fordham’s deliberate attempt to deceive one step further saying, “Their findings show that if anything, increasing charter school enrollment has a positive fiscal impact on local districts.”  That is blatantly false and deliberately misleading.  “Impact” means that the study can support a causal inference.  It clearly does not. But that is not the end of this study’s problems.

The Critical Question Not Posed

There is an obvious question that is neither posed nor answered. How do increases and decreases in district revenue and spending compare to districts without charters? Are the comparative rates higher, lower, or the same?

I read the Fordham report and Weber’s dissertation three times in search of that answer or at least a discussion of the limitation. The author never addresses it.

To ensure I was not misinterpreting the analysis, I emailed Professor Bruce Baker of Rutgers University, a national expert on school finance. He is familiar with Weber’s dissertation, having served as his advisor. I noted in my email that even if increases in revenue and spending are associated with charter growth, it is meaningless unless you can compare those increases to those of other districts with no charter schools.

Baker acknowledged the absence of comparative data and then went one step further (quoted with his permission).

“Comparing districts experiencing charter growth with otherwise similar districts (under the same state policy umbrella) not experiencing charter growth is the direction I’ve been trying to push this with a more complicated statistical technique (synthetic control method).

“But even with that, I’m not sure the narrow question applied to the available imprecise data is most important for informing policy. The point is that the entire endeavor of trying to use these types of data – on these narrowly framed questions – is simply a fraught endeavor and one that added complexity can’t really solve.”

Consider the following oversimplification of the problem. Between 2013 and 2018, national spending on K-12 education has increased 17.6% as states recovered from the Great Recession. That is the average. Spending increases in the states ranged from a 2% decrease in Alaska to a 35.5% increase in California. Both states have charter schools. Vermont, with no charter schools at all, had an 18% increase in spending. Florida, which has an ever-expanding charter school sector, increased spending by 11%. Only Alaska (which Weber does not include) did not see an increase. If we look at this from a national perspective, it is a safe guess to expect that revenue followed an upward slope similar to spending. So did the proliferation of charter schools. And so, frankly, did my age.