Public school is a public good. It’s paid for by everyone for the benefit of future taxpayers, who in turn will do their part. But with public funds paying the bills, public school also should be about making sure everyone has the same opportunities.

That’s easy to say but hard to accomplish for public school districts such as Lawrence, where the community recently built football stadiums for its two high schools. One got standard-issue locker rooms, and the other got locker rooms that are a coach’s dream thanks to an anonymous donor’s gift that some school board members were left wondering whether they should have accepted.

Now they are asking a similar question about full-day kindergarten. The district has 15 elementary schools, each in a neighborhood that has its own strengths and challenges. But only eight of those schools — Cordley, Hillcrest, Kennedy, New York, Pinckney, Prairie Park, Schwegler and Woodlawn — have full-day kindergarten.

The full-day program costs the district about $500,000, which is financed with money restricted to helping students who are considered “at-risk” because of financial or other demographic factors. Adding full-day kindergarten to the district’s seven other elementary schools that currently offer only half-day classes would cost another $650,000, district officials say.

To have a program in one school and not have it at another is hardly fair.

As part of their ongoing redesign of the district’s schools — moving freshmen into high schools, turning junior highs into middle schools and limiting elementaries to kindergarten through fifth grade — Lawrence school board members want administrators to review all programs and determine which ones are the most effective and most efficient.

So, districtwide full-day kindergarten is getting a look. Full-day kindergarten provides many advantages to students, including more time to learn in class and opportunities to develop social skills. It’s where good work habits and routines can be fostered. It has great value for those who can take advantage of it. It shouldn’t be viewed as a day-care service for working parents of kindergartners. It’s much more than that.

The simple, and easy, answer is there isn’t money to have full-day kindergarten at each school. Yes, the district doesn’t expect to receive any more money for the next academic year. And school leaders worry about being forced to make more budget cuts like they had to do this year when jobs and programs were eliminated to reduce expenses by $4.6 million without closing schools.

The question is whether full-day kindergarten is among the district’s best investments for helping improve long-term academic achievement for students, especially those in at-risk groups at all of the district’s elementary schools. If that’s the case, what programs less important than full-day kindergarten might be eliminated?

Is parent-paid tuition an alternative? Lawrence Superintendent Rick Doll said that a sliding scale could be established, allowing students who qualify for free or reduced-price lunches at all schools to receive full-day kindergarten for “free,” while other parents could choose to pay tuition to have their children attend full-day classes.

But that brings us back to the mission of public education. If tuition is the alternative, then the public isn’t doing its job. It should be available to all.

Lawrence administrators and school board members will have to make a tough decision about full-day kindergarten. If it is deemed an important program then it should be available to families who need it and those who want it, no matter where they live in the city.