NEW YORK (AP):

Five years after the start of the Great Recession, the toll is terrifyingly clear: Millions of middle-class jobs have been lost the world over.

And the situation is even worse than it appears.

Most of the jobs will never return, and millions more are likely to vanish as well, say experts who study the labour market. What's more, these jobs aren't just being lost to China and other developing countries, and they aren't just factory work. Increasingly, jobs are disappearing in the service sector, home to two-thirds of all workers.

They're being obliterated by technology.

Year after year, the software that runs computers and an array of other machines and devices becomes more sophisticated and powerful and capable of doing more efficiently tasks that humans have always done. For decades, science fiction warned of a future when we would be architects of our own obsolescence, replaced by our machines; an Associated Press analysis finds that the future has arrived.

"The jobs that are going away aren't coming back," says Andrew McAfee, principal research scientist at the Center for Digital Business at the Massachusetts Institute of Technology and co-author of Race Against the Machine. ''I have never seen a period where computers demonstrated as many skills and abilities as they have over the past seven years."

The global economy is being reshaped by machines that generate and analyse vast amounts of data; by devices such as smartphones and tablet computers that let people work just about anywhere, even when they're on the move; by smarter, nimbler robots; and by services that let businesses rent computing power when they need it, instead of installing expensive equipment and hiring IT staff to run it. Whole employment categories, from secretaries to travel agents, are starting to disappear.

"There's no sector of the economy that's going to get a pass," says Martin Ford, who runs a software company and wrote The Lights in the Tunnel, a book predicting widespread job losses. "It's everywhere."

Job losses predicted

Experts warn that this "hollowing out" of the middle-class workforce is far from over. They predict the loss of millions more jobs as technology becomes even more sophisticated and reaches deeper into our lives. Maarten Goos, an economist at the University of Leuven in Belgium, says Europe could double its middle-class job losses.

Some occupations are beneficiaries of the march of technology, such as software engineers and app designers for smartphones and tablet computers. Overall, though, technology is eliminating far more jobs than it is creating.

To understand the impact technology is having on middle-class jobs in developed countries, the AP analysed employment data from 20 countries; tracked changes in hiring by industry, pay and task; compared job losses and gains during recessions and expansions over the past four decades; and interviewed economists, technology experts, robot manufacturers, software developers, entrepreneurs and people in the labour force who ranged from CEOs to the unemployed.