Last month, an investigation from 60 Minutes and writer Jon Krakauer found that Three Cups of Tea author Greg Mortenson, the raffish philanthropist and founder of 170 schools in Pakistan and Afghanistan, had fabricated parts of his amazing backstory. Worse, 60 Minutes visited 30 of the schools supposedly built by his Central Asia Institute and found half empty or unsupported by the nonprofit. More stories of “ ghost schools ” emerged after the program aired.

The Three Cups of Tea scandal has led to soul-searching and anger among charitable givers and recipients. Nonprofits are scrambling to better account for their dollars. Aid workers in the region are grumbling about the crass imperialist narrative that helped popularize CAI, with a heroic First World dude swooping in to rescue Third World kids.

But the most important lesson of the scandal, and one that hasn’t gotten any attention, is something entirely different. It is a lesson that applies not just to Mortenson’s organization but also to charities that are much-better run: Stop building schools. Or rather, it is a mistake to devote much money or attention to constructing physical school buildings. Throwing up structures is simple. Educating children is a much more complex, expensive, and necessary goal.

“Schools are really easy,” says Saundra Schimmelpfennig, whose organization, Good Intents , seeks to educate donors about nonprofits. “Any kind of a building is really easy to raise funding for, because it is something donors can wrap their minds around. They can see it. They can touch it. It is a one-time expense, not an ongoing or operational cost, which is harder to raise money for. But it is perhaps the least important part of education and the most inflexible as well. Spending all that money building schools is actually pretty questionable.”

Fifty years of research supports this conclusion. Economists and aid experts are continually looking for the best ways to improve educational outcomes for the poor, with an eye to improving health, income, and mobility, too. In the just-released More Than Good Intentions , Jacob Appel and Dean Karlan run through a bevy of the most successful efforts. They include: paying bonuses to teachers with good attendance records, separating kids into classes based on their knowledge and skills, providing tutoring in small groups, and offering deworming pills to students.

“Nice school buildings” appears nowhere in their book. That is because where classes take place—whether in a snazzy school, a private home, a yurt, or a house of worship—generally has little bearing on educational outcomes. It’s the consistency of attendance, health of the student, quality of the teacher, and availability of a good curriculum that really matters. A school isn’t the same thing as an education.

Yet, the conflation of the two remains, much to the frustration of nonprofits. Stories like Mortenson’s—spending millions constructing schools, while neglecting the all-important question of what happens in them—abound. Consider the recent case of Madonna. The Material Girl decided to build a made-to-measure academy for impoverished girls in Malawi. It is bad enough that the charity’s head reportedly spent $3.8 million on things like a car and driver and a membership at a golf course. But it is worse that Madonna’s charity planned to spend $15 million constructing a single school in a country where the entire governmental education budget is just $310 million a year.

Mortenson did manage to get a lot of four-walled structures constructed. Unfortunately, they seem to be expensive and, in many cases, unusable and unnecessary. According to CAI’s 2008 financial disclosure forms , the most recent available, the organization spent a whopping $4.6 million on “domestic outreach and education, lectures and guest appearances across the United States telling Central Asia Institute’s story and the plight of children in Pakistan and Afghanistan.” It spent $3 million on building materials, supplies, and labor for constructing schools. It spent only $759,000 on operating expenses, including teacher salaries, for 141 schools.

Yet, not all of those schools were actually operational, a fact that has come to light in recent weeks. Some communities put the school structures to different use. But other communities never wanted the school buildings in the first place.

Krakauer describes one school for Kyrgyz nomads in the Pamir Mountains as an example. A CAI staffer, as quoted by Krakauer, says, “That’s what they wanted more than anything else in the world—a road. Second, they wanted some kind of health clinic.” One Kyrgyz elder tells the staffer, “If 50 percent of the children die before age five, who is there to educate?” Additional funding for the government-provided teacher who held classes in a yurt might have aided the local population. But CAI instead built a simple, unusable structure at significant cost.