In a new paper for the National Education Policy Center, Mark Weber, educational finance expert, takes a look the problems with the "research" that pro-charter thinky tanks and faux academic departments. "Evaluating Research that Alleges Funding Disparities Between Charter and School Districts" is an excellent summation of the problems that have been repeatedly pointed out over the years. It's a worthwhile read, even if the title seems scary; NEPC is absolute aces when it comes to rigorous, legitimate research expertise, but sexy titles are not their thing.
Weber notes that third party reviewers have often called these folks on their errors, and while they have occasionally addressed the issues, "they have retained core deficiencies in their methods" with the result that "they continue to report large funding 'inequities' where none exist." Weber diplomatically skips over the question of whether this core deficiencies result from ineptitude or deliberate misrepresentation.
Here are the research flaws that Weber addresses.
Inadequate documentation of data
Not everyone reports financial data the same way, so that some deliberate steps are needed to deal with comparing apples to oranges. That means that sources for data have to be transparent, and it requires extra legwork to check your work. That means any attempt to compare public schools and charter schools will have limitations. Weber points out those limitations won't be fatal to research, but they necessitate a full explanation to the audience of where the numbers came from and how they were arrived upon. If you're going to tell me that you can make more applesauce with a pile of oranges than with a pile of apples, you need to show your work. In detail. Otherwise I might suspect you're juking the stats behind your back.
Misunderstanding of financial transfers
The first time I came across this criticism of some charter "research," I thought maybe I was misunderstanding, because nobody could seriously do this. But this "misunderstanding works two ways.
One. This deals with how public schools pass through the funding for charters. East Egg Public Schools get $1,000. Eggly Charter gets $250 of that for its students. That $250 gets counted twice, both as the public funding and the charter funding. Or, to put it another way, the public charter is counted as having $1000 when it actually ends up with $750.
Two. The public system pays for things that benefit both public and charter (e.g. in California, food and special ed services). So some of that money is being spent on charter students, but it is only counted by these researchers as being spent only on public school students.
tricks misunderstandings would be enough to create "research" that "proved" that public schools were spending more per pupil than charters.
I'm not saying that Weber is being excessively generous in calling this a misunderstanding, but I am saying that when the misunderstanding was pointed out to researchers in a previous piece of research, they did not stop doing it.
Invalid conflation of individual schools and school districts as units of analysis
Weber argues that "the most relevant unit for school finance is the district." Charters function as single-school districts (though I'm curious how charter chains could be handled), but studies tend to compare single school to single school.
That creates another data problem, because some district expenditures are attributed to the entire district as a whole, not individual buildings. That's not an insurmountable barrier, but Weber says researchers skip the work required by simply pretending that district-wide expenditures can be divided out as per pupil spending--except that this is generally wildly inaccurate, as districts may dispense some of that funding by methods other than simply per pupil.
Invalid comparisons of student populations
Huge amounts of spending disparities come down to students with special needs (particularly since public schools have many and charters have hardly any). So if you're going to break down per pupil spending, you need to look at what kinds of students the spending is aimed at. A school of 100 high needs students will spend more per pupil than a school with 100 regular students (and we know that public schools tend to be the former and charters tend to be the latter).
I'll note that if you're in Pennsylvania, it gets even wackier, because public schools sort students into different tiers of special needs, but charters are reimbursed as if all special needs students are the same.
Invalid comparisons of the functions of charter and district public schools
Weber says that one report tries to make a distinction between purpose and work of schools in order to make the argument that, hey, public and charter schools are both for educating the public, so we should be comparing the money they take in, their revenue, rather than how they spend it.
But, Weber correctly points out, they aren't set up for the same purpose. Public schools are set up to educate everyone, which means they have to have the revenue necessary to deal with all manner of student needs. It also means that public schools much maintain excess capacity, while charters can cap admissions. Some school districts are also set up to provide community services, adult education, and a variety of other purposes that involve revenue that is not spent on K-12 students.
Unaccounted for charter revenues
Public schools get money from the taxpayers. Charter schools, in many cases, get money from philanthropists.
Charter proponents sometimes try to equate revenue from cafeterias and facilities rental with philanthropic giving. But the examples from public schools involve people paying for the costs of a service; philanthropists are not paying for anything (unless, I suppose, charter fans want to talk about specific services they provide their philanthropic donors).
Taken one or two at a time, or all together, these factors raise large questions about the accuracy of any comparisons between charter and public school funding and certainly have to be considered before accepting any claims that charters are put upon and underfunded. As Weber notes, charter advocates have cranked out many "reports" that suffer from these flaws. There may be conversations worth having about charter funding, but they aren't worth having if they aren't based in reality.
In the meantime, you can check out the full paper at NEPC. It comes complete with examples of various papers filled with these flaws, as well as explanations of how the flaws could be avoided. We can only hope that charter advocates take some of that advice to heart.