BOSTON — There is a deep unease spreading across the United States.

As anyone who's living through it can tell you, America's middle class — the backbone of the world's largest economy — is in distress.

The numbers tell the story:

Median family income in America peaked in the year 2000. Since then it is down some 6 percent, the worst 12-year stretch for the middle class since the Great Depression.

Meanwhile many of the jobs that once employed this group have moved overseas or have been replaced by new technologies, a big problem for one subset of the middle class: the 5 million out-of-work Americans who the Labor Department calls the "long-term unemployed."

In short, America's middle class is being gutted by a variety of complex and interrelated factors, and this economic pain is increasingly evident to those at the center of it.

According to an August survey by the Pew Research Center, 85 percent of middle class Americans say it is more difficult today to maintain their standard of living than it was 10 years ago.

This seismic shift is decades in the making and transcends Democratic and Republican parties and politics. It was exacerbated by the Great Recession of 2008, which decimated the US job and housing markets, a key source of middle class income and wealth.

The implications are profound and troubling.

As this middle hollows out, millions have fewer financial resources for their families, and less spending power to help fuel the consumer-based US economy.

Millions more are losing hope that their country can provide good jobs now or in the future.

Many are questioning the very ideals of America, and what the country's historic opportunity once represented to the rest of the world.

But America's problems are not the whole story.

Over roughly the same period as the middle class decline in the US, huge numbers in the developing world have enjoyed big increases in their standards of living — notably in China and India, as well as other countries in Asia, Latin America and beyond.

While the Great Recession has challenged some of these high-flying places, the long-term trend is clear: more people around the world are expected to ascend into the middle class.

According to scholar Cheng Li of the Brookings Institution Press, by 2030 "5 billion people — nearly two-thirds of the global population — could be middle class."

What does this complex trend mean for people around the world? How is it playing out in shuttered factory towns across America? How is it changing lives — for good and sometimes ill — in the emerging boomtowns of the developing world? What is the future for the middle class in the US?

These questions and more are the focus of a 10-month GlobalPost investigation, America the Gutted.

In this worldwide reporting project, GlobalPost's award-winning team of journalists will tell the stories of American middle-class workers who have lost their jobs across a number of industries, and who are today struggling to make ends meet.

On the flip side, we'll also profile workers around the world who now own the jobs once held by America's faltering middle class — in China, India, the Philippines and elsewhere.

It's our goal to humanize this global economic shift by telling real stories of real people — across text, video and photography.

Along the way, we'll be using this America the Gutted blog to tease out some of the project's larger themes and original reporting. We'll also point to related news stories from around the world and, yes, on the US presidential campaign trail, where a sharp debate over America's economy could define the election.

Then, in early October, we'll launch the full America the Gutted reporting project on GlobalPost.

We hope you'll join us.

And please feel free to offer your own stories and thoughts in the comment section below. This global trend concerns all of us, no matter where you happen to live.

Here's more on why we're covering this: