Something is happening to the independent charter schools that have taken over public education in New Orleans — they’re becoming a little less independent.

No, they aren’t rushing back to the elected board that used to govern all of the city’s public schools. But charters in New Orleans are more and more finding themselves parts of big and growing networks that share key staff, board members and ideas under a single leader, or CEO.

While these networks — charter management organizations, in education lingo — have existed for years in New Orleans, they are increasingly the norm as go-it-alone schools continue to dwindle. A few years ago, there were almost two dozen standalone charters in the state-run Recovery School District, representing about a third of the total; by next school year, there could be as few as seven or eight.

Pooling resources, of course, can drive down costs, and educators say fewer walls between schools can allow new ideas to spread more quickly. In part, also, the trend has accelerated because of a simple weeding-out process: Schools that succeed are asked to double down on what works and take on more students, while struggling operators get shut down.

Good schools “have a model they can replicate,” said Maggie Runyan-Shefa, the co-CEO of a nonprofit called New Schools for New Orleans, which has helped decide which schools get special federal grants for expanding.

At the same time, Runyan-Shefa acknowledged the potential downside of a school system increasingly dominated by just a few operators: fewer approaches to instruction competing with one another and fewer choices for parents in a system that is supposed to maximize options. “We want to make sure innovation spurs competition in the system,” she said.

The drift toward charter consolidation is part of a broader swing of the pendulum in New Orleans. The idea — ascendant since Hurricane Katrina — that parents should have choices and that schools should have autonomy remains central. But other priorities have pushed schools toward a more centralized approach in certain respects.

To make sure parents can find a place in the patchwork of different school operators, state officials launched a centralized enrollment system. To ensure students aren’t unfairly expelled, the Recovery School District now holds expulsion hearings at a central office.

The growth of charter management organizations, or CMOs, hasn’t come about because of any sweeping policy change. In part, it always was the plan.

Operators like KIPP, which now runs 10 separate schools in New Orleans and could eventually grow to 12, always have envisioned expanding in order to serve more students and take advantage of economies of scale.

On the other hand, ad hoc decisions by state officials have contributed to the trend as well.

A standalone charter high school in New Orleans East called Miller-McCoy Academy recently turned in its charter after state officials told school leaders how unlikely a renewal would be. As with other schools that have struggled academically, the state probably will turn to one of the city’s other charter operators to run a school out of Miller-McCoy’s new building. And the groups that have applied to take over the building will either move an existing school to the site or expand their network with a new campus.

Going bigger has some obvious benefits, particularly when it comes to tackling complex and sometimes expensive problems like special education.

KIPP, for instance, is in the midst of expanding classrooms for students with severe disabilities. KIPP McDonogh 15 in the French Quarter is already running such a classroom, while two other KIPP schools are just getting started. So Jessica Taylor, who helps run the McDonogh 15 program, is training her counterparts from the other campuses. That way they won’t have to start from scratch.

“I’ve already figured out how to do grades. I’ve figured out how to do reading,” Taylor said.

Meanwhile, KIPP can afford to hire staff that a standalone school might not. The KIPP network has three full-time psychologists and four full-time speech therapists who split their time among its campuses.

Kate Mehok, who founded a group called Crescent City Schools that has grown from one to three campuses, says expansion has allowed her principals to focus on coaching their teachers and improving instruction. The work of thinking through long-term strategy, communicating with the group’s nonprofit board or talking with reporters falls to Mehok, the group’s CEO.

At a standalone school, Mehok said, “You’re asking your principal to do both of those jobs, and that’s really hard.”

For charter school proponents, the danger in all this is that charter schools might begin to re-create the big, centralized districts they were meant to replace.

Advocates credit the more decentralized approach to organizing schools with raising test scores in the years after Katrina. And they fault centralized bureaucracies, which still have a monopoly on public education in many cities, for stifling reform efforts.

Robin Lake, director of the Center on Reinventing Public Education, said her group has studied CMOs around the country and found that some of them run into trouble when they get too big, even though many big networks get good results. “We saw CMOs becoming much more bureaucratic,” she said. “There’s more distance between teachers and management.”

Kathleen Padian, who runs the Orleans Parish School Board’s charter schools office, said she worries about big CMOs grabbing too much market share and snuffing out innovation.

The parish board, which lost control of most schools in New Orleans after Katrina, does not have the kind of big CMOs that exist in the RSD. But that could be in part because charters that still fall under the board’s jurisdiction get some of the central-office supports that those in networks do.

Meanwhile, some of the board’s charters, like the magnet school Lusher, have grown bigger by simply adding grades. And one or two others have an eye on expanding eventually.

That’s in part why her office continues to ask for new charter applications, Padian said. Her pitch is: “Come to us with something we don’t have already.”

Editor’s note: This story was changed Jan. 20 to reflect that Miller-McCoy officials voluntarily turned in the school’s charter after state officials warned them it was unlikely to be renewed.