NEW YORK – It stands to reason that the more instructional time students receive in school, the more they will learn.

That simple premise is one of the main reasons many charter schools do a better job of educating students than government-run schools. The alternative public schools – which are typically nonunionized – can offer longer schools days without first going hat-in-hand to the local teachers union for permission.

The result is often higher test scores and on-time graduation rates for charter schools.

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But now there might be a way public schools can offer longer school days without first reaching an expensive agreement with their self-centered teachers unions.

In an op-ed for CrainsNewYork.com, Citizen Schools official Kathrine Mott notes that some schools are using volunteers – instead of unionized teachers or school personnel – to extend the school day. The longer days allow students to take part in tutoring sessions, science clubs, music lessons and other “enrichment activities” that are normally out-of-reach for low-income students.

Mott, who serves as the executive director for Citizen Schools’ New York chapter, writes:

“We are already seeing evidence that this can improve academic outcomes. With my organization, Citizen Schools, as a partner, dozens of public middle schools serving low-income communities across the country – including the Bronx, Harlem and Brooklyn – have extended their days by three hours and provided enhanced academic support, enrichment and college preparation.”

Mott adds that students in Citizen Schools programs are “outperforming peers on state tests (growing at rates that match or surpass those of esteemed charter networks)” and “are also graduating from high school at a 20 percent higher rate and closing the college-enrollment gap completely.”

From the Citizen Schools’ website:

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“Students in upper-income families spend 300 more hours each year with adults than do the three million students in lower-income families. Upper-income students also benefit from almost $8,000 worth of enrichment activities yearly—robotics camp, piano lessons, academic tutoring, and more.

“We can close this gap, and help … students discover and achieve their dreams, by connecting students who want to learn and adults who have something to teach…families with big dreams and volunteers with big hearts…visionary school leaders and a non-profit with a proven model…citizens and schools.”

This program seems like a great way of helping students without getting bogged down in the extra pay demands and work-rule requirements of teacher unions.

Of course, even using volunteers, the longer school days will lead to more expenses for schools – such as higher electric and heating bills, custodial costs, etc. Mott suggests that some of those increased expenses could be offset with donations “from corporations, individuals and foundations that want to invest in public education.”

Conservative donors who would never give public schools a penny out of fear it will end up in the pockets of left-wing teacher union leaders might be enticed to support such a program.

Mott admits that more tax dollars might be required, too.

As for who would staff the extra three hours a day, Mott suggests that could be handled through the “publicly funded AmeriCorps teaching fellows and volunteer-teachers from local companies.”

It’s an intriguing idea that’s certainly worth considering.

Citizen Schools, which was founded in 1995, currently has six locations in the U.S.