It is fun reading of 30- and 40-somethings who seek a more pleasant life by moving into small towns in our region, bringing with them energy and new ideas.

But you have to wonder if the economic gravitational pull of big cities isn’t simply too strong for this to become much of a sustainable trend.

Most Minnesotans live in our big Twin Cities metro area, of course, which happens to be one of the few in the Midwest that is on the list of the nation’s 25 biggest metro areas, and the only Midwestern one that is really growing.

The state’s fastest-growing counties since 2010 are in the Twin Cities, led by Carver County, and the growth of the metro area was enough to boost the whole state’s population by about 6% since 2010, according to the state demographer’s office.

More than half of Minnesota’s 87 counties, on the other hand, saw a decline in population since 2010.

Rural Martin County, where I’m from, shares a border with Iowa in southwest Minnesota. It saw its population decline from the 2010 census by about 5%, according to census estimates. Out in western Minnesota, where my mom grew up, Lac qui Parle County saw its population slip about 8% since 2010.

The growth of the Twin Cities can’t be explained by having more appealing restaurants or shiny stadiums. I grew up a Vikings fan nearly 150 miles from where the team played. A far better explanation is the metro area’s relative abundance of one of the most important factors these days in economic growth. That is ideas.

Not long ago, conventional economic thinking didn’t account much for ideas or technology, just the supply of labor and capital items like more machines.

Researchers knew this didn’t give them the most complete picture, with some additional productivity obviously coming from know-how or new technology. Among the leading thinkers who helped develop a far better understanding of this is Paul Romer, who shared the Nobel Prize in economics last year.

One of the most interesting things about the role of ideas and know-how in growth is that they have far different attributes than a new factory or 100 additional workers.

It is obvious that a new factory, however cleverly designed, can only be used by one party at a time. Same for a new worker, who produces something for either the Ajax Co. or the Acme Co., not both at the same moment.

Ideas don’t work that way. More than one person can productively use the same idea at the same time. In fact, any number of people can, provided they have somehow learned about it. And that is one way metro areas turn out to be really important.

The originator of a clever idea didn’t really mean to share it with everybody else in the business, but over time that can happen. This movement of ideas often takes place in face-to-face conversation. When employees take a new job with a new employer, for example, they can’t pretend they didn’t learn some effective ways of organizing the work at their last job.

Ideas can also move around in informal, almost random ways, like between two people standing on the sidelines of youth soccer matches.

One of the things that helps a regional economy grow is having more people working in what is called the knowledge sector, trying to come up with new stuff. That means both generating more ideas and having more people bump into them, refining them and trying to apply them in ways that make money.

That is why budding technology entrepreneurs head for the San Francisco Bay Area. It is not like they haven’t heard how expensive it is to rent a place to live in Silicon Valley or how difficult it can be to recruit staff. They are just hoping to jump into that region’s vast swirl of ideas and know-how.

This is one explanation for why incomes are higher in metro areas. The median household income in fast-growing Carver County, in the southwest corner of the Twin Cities metro area, is around $101,000, about twice that of Lac qui Parle County.

Moving into the metro area to train for high-paying jobs might seem like a no-brainer, but of course there is another side to the equation. This shows up in survey research provided by the Blandin Foundation, an organization in Grand Rapids, Minn., that has long worked in rural development.

It is true that those who are living in rural areas but thinking about moving want better job opportunities, the survey concluded. But there are far more people living in metro areas thinking about moving the other direction. The most cited reason? Quality of life.

As she was pulling together this information, Blandin’s Allison Ahcan reminded me of Christopher Ingraham, a writer for the Washington Post now living in Red Lake Falls.

As Ingraham wrote in his new book, “If You Lived Here You’d Be Home By Now,” his family thought it over and decided to leave the East Coast for northwestern Minnesota. His story is a great reminder about the dangers of thinking you really know something about a place and its people based on not much information.

Ingraham learned of Red Lake County by writing a short item in 2015 that labeled it the worst place to live in the country, as ranked using U.S. Department of Agriculture data. Not long after, following a pleasant visit to the area, he and his wife were talking about the relative merits of living there.

Housing and child-care in greater Washington, D.C., are very costly, and commuting to and from work can be a long, lonely and stressful daily grind. One little chart in Ingraham’s book showed that the median price for properties for sale in Washington, D.C., is nearly $500 per square foot, while in Red Lake County that price is just $53.

Stress-free commutes to work from your easily affordable, big house sound great, of course. But the relocation of Ingraham’s family wasn’t enough to keep Red Lake County off the long list of Minnesota counties that experienced a population decline over the past decade.