What do Honolulu’s high schools and a new athletic complex in Milwaukee have in common?

The high schools indicate a problem in achieving the American Dream. The Milwaukee athletic facility is one of the ways to achieve that dream.

Here’s why. It’s all about having the right kind of friends. If you are poor, you need some friends who are well off.

Low-income students who had attended Oahu’s public high schools were much less likely to have relatively well-off friends than poor kids attending private schools, according to an atlas that maps the distribution of “social capital.”

Eighty-five percent of low-income students who went to Iolani had well-off friends while at Kaimuki High, across the street, less than half did.

If you were a low-income kid in a school in a better-off neighborhood, you were more likely to have some well-off friends than in low-income areas like Waianae and Nanakuli.

The Milwaukee facility is part of a solution to this problem because venues for athletic activities have considerably more rich-poor friendships than schools do.

The Milwaukee complex will be in a neighborhood that borders the relatively poor, heavily African American city and its heavily white suburbs.

It will be a place, as a key funder describes it, “where city limits become invisible, and people will get curious about one another and spark meaningful connections.”

What makes this comparison especially significant? Here’s a hint: The Milwaukee complex will be named The Opportunity Center. That’s significant. So is their use of the word “connections” because more than anything else, those connections are the most important generator of economic opportunity.

These low-income/high-income connections are by the best driver for achieving the American Dream.

For the last half century, the American Dream — moving up by doing better economically than your parents — has in fact been the American Stagnation.

Children from lower income families are more likely to stay poor than they were back then. Overall, the country is less equal. This pattern has been stubborn, protracted and getting worse.

To get your head straight, it helps to think of this friendship stuff as hard-ass economics rather than kumbaya pap.

The usual attempts to change this have hardly made a dent because, as it turns out, we have been looking for solutions in all the wrong places.

Here are the key findings from the economist Raj Chetty and his colleagues’ recent, definitive, pioneering research involving U.S. adults between 25 and 44, over 74 million Facebook users and billions of Facebook messages:

For poor children, living in an area where people have more friendships that cut across class lines significantly increases how much they earn in adulthood.

Chetty calls these friendship patterns “economic connectedness.” There are good sources, including an interactive way to look at this mass of information and video, here, here, here and here.

People who grew up in low-income families but who also had higher-income friends are far more likely to break the American Stagnation chain and move up quite considerably. No other factor comes even close.

To get your head straight, it helps to think of this friendship stuff as hard-ass economics rather than kumbaya pap.

Here is a story showing how this works. It’s a profile of a woman from a low-income family who attended a California public high school with a high level of cross-class friendships.

Those relationships benefited her in three big ways. The mix first made her curious. (Remember the Milwaukee facility’s objective to increase curiosity and spark connections?)

Then those friendships raised her ambition, helped her get information about applying to college and established networks that became useful down the road.

She also had a mother who strongly encouraged her and a public school that drew a very diverse body of students. But as that former high school student sees it, the friendship mix was the biggest force.

She’s now a criminal defense lawyer.

Seventy percent is a threshold because that’s the share of high-income students’ friends who are wealthy. If 70% of a low-income student’s high school friends are well-off, she is likely to increase her future income by 20%.

Using this measure, Oahu’s private high schools do much better than its public high schools. Most Oahu private high schools score well over 70% for lower-income students while only one public high school does.

Only about a quarter of Waianae and Nanakuli high school students had friends with higher economic status. Leilehua is a bit higher.

Most of the rest of the public schools are in the 60% range — not bad but not up to that 70% threshold. If you look at connectedness on Oahu overall (not just schools), we do OK but not great compared to the mainland.

In Hawaii we talk about connectedness all the time — aloha, ohana, neighbors sharing stories and food, high school reunions.

These are of course different terms than those used by Chetty or other important writers about social capital like Robert Putnam, who wrote “Bowling Alone.”

Are those Hawaii-based things like ohana and aloha manifestations of connectedness, strong social capital? We don’t know because we don’t investigate.

It amazes and frustrates me how little we know about how Hawaii works from the ground up, which is what you need to know to understand connectedness. We have terms but no real information.

That’s not how we write our history of Hawaii. It’s also not how we think about our politics. We have nothing like that profile of the young woman’s high school experience. Nothing about social networks.

The stories we tell of ourselves tend to be about small things, but when we think of and act out our politics, the importance of these little things get lost.

There is a recent exception, and it comes from a surprising source — Tom Coffman’s book about Hawaii’s Japanese American community in World War II.

You’ve probably heard the story of how John Burns and other muckety-muck community leaders convinced the military government here not to imprison all of Hawaii’s Japanese.

Coffman shows that the full story is more complicated, less about big shots and more about networks of regular local guys, no-names who hung out at the Y and over time became a key — but never all that visible — force in tamping down the military’s enthusiasm for locking ’em all up.

This power of connections continued to be valuable after the war.

Think of something called “A Hawaii Equality Story.” The beginning would be a troubled economy where some people are doing very well while most are not. Hardly anyone moves from low income to high income. There is no real sign of  progress.

The happy ending of the story is a Hawaii where the American Dream turns into a reality.

Right now, though, the critical middle of this story — how to get from the sad beginning to a happy ending — is missing. Looking at Hawaii through the eyes of Chetty’s data and intervening accordingly is one key method to fill this hole. Another is to look more closely at how friendships develop and work.

When it comes to the economy, Hawaii is full of big dreams. They usually don’t pan out.

One of the reasons may be that we haven’t realized how much small things are necessary to make big things happen.