Long ago, I was captivated by a seductively intuitive idea, one many of my wealthy friends still subscribe to: that both poverty and rising inequality are largely consequences of America’s failing education system. Fix that, I believed, and we could cure much of what ails America.

This belief system, which I have come to think of as “educationism,” is grounded in a familiar story about cause and effect: Once upon a time, America created a public-education system that was the envy of the modern world. No nation produced more or better-educated high-school and college graduates, and thus the great American middle class was built. But then, sometime around the 1970s, America lost its way. We allowed our schools to crumble, and our test scores and graduation rates to fall. School systems that once churned out well-paid factory workers failed to keep pace with the rising educational demands of the new knowledge economy. As America’s public-school systems foundered, so did the earning power of the American middle class. And as inequality increased, so did political polarization, cynicism, and anger, threatening to undermine American democracy itself.

Taken with this story line, I embraced education as both a philanthropic cause and a civic mission. I co-founded the League of Education Voters, a nonprofit dedicated to improving public education. I joined Bill Gates, Alice Walton, and Paul Allen in giving more than $1 million each to an effort to pass a ballot measure that established Washington State’s first charter schools. All told, I have devoted countless hours and millions of dollars to the simple idea that if we improved our schools—if we modernized our curricula and our teaching methods, substantially increased school funding, rooted out bad teachers, and opened enough charter schools—American children, especially those in low-income and working-class communities, would start learning again. Graduation rates and wages would increase, poverty and inequality would decrease, and public commitment to democracy would be restored.

But after decades of organizing and giving, I have come to the uncomfortable conclusion that I was wrong. And I hate being wrong. What I’ve realized, decades late, is that educationism is tragically misguided. American workers are struggling in large part because they are underpaid—and they are underpaid because 40 years of trickle-down policies have rigged the economy in favor of wealthy people like me. Americans are more highly educated than ever before, but despite that, and despite nearly record-low unemployment, most American workers—at all levels of educational attainment—have seen little if any wage growth since 2000.

To be clear: We should do everything we can to improve our public schools. But our education system can’t compensate for the ways our economic system is failing Americans. Even the most thoughtful and well-intentioned school-reform program can’t improve educational outcomes if it ignores the single greatest driver of student achievement: household income.

For all the genuine flaws of the American education system, the nation still has many high-achieving public-school districts. Nearly all of them are united by a thriving community of economically secure middle-class families with sufficient political power to demand great schools, the time and resources to participate in those schools, and the tax money to amply fund them. In short, great public schools are the product of a thriving middle class, not the other way around. Pay people enough to afford dignified middle-class lives, and high-quality public schools will follow. But allow economic inequality to grow, and educational inequality will inevitably grow with it.

Read the rest of Nick Hanauer’s article at The Atlantic