Danny Westneat: Bill Gates, have I got a deal for you!

At Lakeside, Seattle's premier school, they say the graduates know better than anyone what makes the place so special.

"Ask any alumnus what the best thing about Lakeside is," the school's brochure urges. "And they will likely mention an environment that promotes relationships between teachers and students through small class sizes."

Any alumnus? Because one in particular is now going around saying the opposite.

Bill Gates lately has been arguing that smaller-sized classes are among the biggest wastes of money in all of education.

"Perhaps the most expensive assumption embedded in school budgets — and one of the most unchallenged — is the view that reducing class size is the best way to improve student achievement," Gates said last week to a gathering of governors.

Smaller classes just haven't worked, he said.

"U.S. schools have almost twice as many teachers per student as they did in 1960," he said. "Yet achievement is roughly the same."

Gates called for an end to state caps on how many kids can be in each classroom.

Now let me clarify: Gates is suggesting larger classes in public schools. Not private schools such as Lakeside or the ones his own kids attend today.

Public-school classes already are growing, due to the recession. Add in someone as influential as Gates saying it can be the right thing to do, under the right circumstances, and look out.

So — is he right? Can we improve education by increasing class size?

Well, as with everything in education, there's no easy answer. Gates' argument is hardly reassuring to those of us whose kids are the ones about to be experimented on.

For starters, that the U.S. has added teachers in the past 50 years and yet seen only moderate gains on tests doesn't prove smaller classes are a waste. There are countless other variables at work, from more non-English speaking students to the rise of special ed to major family and societal changes.

Research has shown small classes are most crucial when kids are young, but less so as kids grow up. That's why the focus in this state has been on driving classes down to about 17 kids for kindergarten through fourth grades.

Most remain far more crowded than that. So one could just as easily argue it hasn't worked because it hasn't been tried yet.

Gates put up a slide in his speech showing that a third of all school employees today don't work in classrooms. In the search for savings, I'd start there.

But Gates didn't. Instead, he proposed adding six students to the classes taught by the best teachers, then using the money saved to pay those teachers more. He said Gates Foundation research has found that teachers would be happy to have more students for more pay.

I looked up that study, done at the UW in 2008, and what it actually says is teachers prefer a $5,000 pay boost to having two fewer students. They weren't ever asked about more students.

We're lucky to have Gates — he both means well and uses his means well — so I don't want to get too personal here. I bet he senses deep down as a parent that pushing more kids into classes isn't what's best for students. His kids' private-sector grade school has 17 kids in each room. His daughter's high school has 15. These intimate settings are the selling point, the chief reason tuition is $25,000 a year — more than double what Seattle schools spends per student.

Bill, here's an experiment. You and I both have an 8-year-old. Let's take your school and double its class sizes, from 16 to 32. We'll use the extra money generated by that — a whopping $400,000 more per year per classroom — to halve the class sizes, from 32 to 16, at my public high school, Garfield.

In 2020, when our kids are graduating, we'll compare what effect it all had. On student achievement. On teaching quality. On morale. Or that best thing of all, the "environment that promotes relationships between teachers and students."

Deal? Probably not. Nobody would take that trade. Which says more than all the studies ever will.

Danny Westneat's column appears Wednesday and Sunday. Reach him at 206-464-2086 or dwestneat@seattletimes.com.