By James H. Lytle

Given the frequent and considered attention to the challenges and prospects of public schooling in Philadelphia, it may help to have a clearer understanding of why the city's district schools are having such difficulty competing with charter schools.

Although this is a simplification, it's reasonably straightforward to explain why charter schools have a substantial advantage. Imagine a charter school with 700 students. It receives approximately $10,000 per student each year from a combination of state, federal, and local government allocations; its 100 special-needs students get an additional $10,000 per year, adding $1 million to the school's annual budget of $8 million a year.

The school needs 35 teachers to have class sizes of 25 or less. Assume average salaries of $50,000, plus a 20 percent benefit cost, for a total cost per teacher of $60,000. So the core cost of instruction is $60,000 multiplied by 35, or $2.1 million. That pays for a longer school day and school year than district schools, which are important for students and parents, and for teacher planning and professional development time.

The balance, $5.9 million, is available for administration; support staff (nurses, counselors, arts and music, security, maintenance, food services, secretaries); technology, books, and materials; summer programs, equipment, utilities, facility maintenance, and lease/purchase - more than sufficient to provide the programs, services, and support students deserve.

District schools, on the other hand, are caught in an array of recurring costs that severely limit their ability to compete, including collective bargaining agreement provisions, a poor credit rating, debt service, maintenance of aging facilities, high-need students, transportation. District schools get marginally higher per-pupil budget allocations than charter schools but pay twice as much for teaching positions as charter schools do - for 2016-17, almost $120,000 per position, primarily because the state is requiring all public school districts to make up the deficit in the state pension fund. (The employer pension rate has increased from zero in 2001-02 to 29.2 percent of salary in 2016-17.)

Unlike the district, charter school employers do not have to participate in the state retirement fund and have the option of instead offering "approved retirement programs" to their employees (for example, 403[b] plans). There is no mandatory contribution amount, and such plans may be based on employee contributions and/or employer matching arrangements. And because charter school teachers tend to be younger than district teachers, they are less concerned about retirement and health benefits, and the benefit cost to their employers lowers.

The significance of the teacher price differential is that next year, 35 teachers at a district school will cost $4.2 million. Most of the remaining balance will be controlled by central administration and designated for overhead expenses, so schools will have very limited discretionary funding.

The political and policy environment also favors charters. Since the passage of No Child Left Behind in 2001, federal K-12 education policy has encouraged charter school development and made conversion from district to charter school a key provision of intervention in low-performing schools. In Pennsylvania, the legislature has reinforced this approach, providing strong support for "marketizing" K-12 schooling, both through its Opportunity Scholarship (voucher) program and through aggressive support of charter schools. Another consideration is the state Supreme Court decision suspending the School Reform Commission's charter school enrollment caps, which means charter enrollments will likely increase as operating agreements are renewed, accelerating the transfer of district funds to charters.

Parent demand for charter placement far exceeds supply, and district schools cannot offer the range of programs and services, or the assurances of safety, that charters do. On the strength of their competitive advantages - financial, political, and programmatic - charter schools are likely to become the predominant form of public schooling in Philadelphia, although there is no evidence to date that they do better at improving student achievement than district schools.

Of greater concern is the fact that the city's charter schools amplify the race and class disparities and segregation that characterize district schools, and enroll proportionately fewer special-needs students, English-language learners, and students whose families aren't attuned to how the market works.

The big question is obvious: What are the implications of charter-school growth for the city? Is this transformation to charters leading to the public education "system" we want? Can the historically democratizing purposes of public schools be sustained in a balkanized system with little central oversight?

In my view, these questions have everything to do with the city's future. For that reason, I'd urge the mayor, City Council, the SRC, and state and federal legislators to initiate a dialogue with parent and public-interest organizations on the future of public schooling in Philadelphia.

James H. "Torch" Lytle is an adjunct practice professor of educational leadership at the Graduate School of Education of the University of Pennsylvania and a former superintendent of the Trenton public schools. jhlytle@gse.upenn.edu