A violin bow-maker lives a couple hundred yards down the street from my home. He just won a MacArthur genius grant.

His grandmother was a famous concert pianist in France. And by the time he turned 7, she had him playing the instrument. By 9, he was a violin student at the Versailles conservatory. And by 16, he was a graduate of the Conservatoire de Paris. But the more he played, the more fascinated he became with the stick and horsehair that generated the sounds. He soon gave up the notion of a career as a musician and committed himself to making bows.

“It is an ancient craft worldwide, but especially treasured in France,” Rolland said. “And I have no better explanation than that I simply love the bow. It is necessary. So important. Much like the instruments they serve, I see the bows as living entities, not unlike muscles in the body.

“You move them differently, they produce different sounds. You shape them differently and mold them differently and the results vary.

The guy works hard.

Christine Arveil, Rolland’s wife, says it isn’t uncommon for him to spend up to 12 hours a day, seven days a week in his home studio in Watertown. There Rolland fashions the Brazilian Pernambuco wood that comprises the handles of violin, viola, and cello bows. He painstakingly threads the taut horse hair ribbon that is drawn across an instrument’s strings and lovingly shapes the metal “frog” that allows musicians to alter the pitch and tone of their playing by sliding it along the strings.

He doesn’t own a television, because it would be a distraction. He relaxes by playing violin, writing music, and sailing. He only occasionally he has time to read a book for relaxation and not research.

“I know it seems like a cliche,” Arveil says. “But he loves the bows and dotes on each one as a child he’s preparing for adoption — but only after having gotten to know the adoptive parent.”

Another local MacArthur winner is a Harvard economist, Raj Chetty. He rote a notable K-12 paper recently.

In a study on teacher quality using these data sets and information gleaned from school district databases, Chetty and colleagues found that, adjusting for other factors, students who by chance were assigned to talented teachers in elementary school had significantly higher incomes as adults and better future life outcomes more generally.

Remember, that's a thorny, hotly debated issue.

1. We all agree it's hard to get test scores to go up.

2. But when the scores do go up, is that a narrow win ("learned to take test") or a life win (better income, better family, more happiness, less prison, etc)?

Chetty's work suggested: life win. But that's just one paper.

And the effect size wasn't amazing when you first look at it. More like "nice." $1,000 per year of additional income later in life for the kids who got the excellent grade K teacher (as measured by Value Add) instead of the so-so teacher.

Now if you package that annual income gain together, you get a more stirring paragraph.

“If you add that up over a student’s working life, and adjust for inflation and interest rates, you get a total lifetime gain of around $16,000 per child.”

In a classroom with an average of 20 students, then, an excellent teacher means a total gain in earnings of $320,000 for the entire class. And students from small classes experienced other important advantages: they were more likely to attend college, to own a home, and to save for retirement.

And of course if you imagine what would happen if a kid would also get an excellent Grade 1 teacher, Grade 2 teacher, etc, then the effects can start to look "big."

But that question -- when we are lucky enough to see the kid doing better on math and English tests, does that uptick really predict he'll do better in life? -- will be with us for a while.

Yesterday a scholarly friend showed me a new paper he'll publish in a month. It analyzes a similar question pertaining to charter schools. The results were not what I'd expected. I'll share it once it's out.