By Mohamed A. El-Erian

A strange thing is happening in the U.S. labor market: The unemployment rate has been falling much faster this year than it should given the slow underlying pace of economic growth.

In fact, the fall in joblessness has exceeded that projected by policy makers and private-sector economists, the majority of whom had expected much faster economic growth. It's a conundrum that policy makers can't allow themselves to dismiss too easily or too quickly.

How much one should worry about the jobs-growth gap depends to some extent on why it's occurring.

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One possible explanation focuses on measurement issues. Statisticians use different data sets and methodologies to estimate unemployment and economic growth, so it's not uncommon for the two to diverge temporarily. That said, the gap is large and widening, and most economists expect it to persist at least through the end of the year.

A second explanation is that the relatively rapid decline in unemployment is simply payback for the early part of the recovery, when economic growth outpaced the decline in joblessness. Coming out of the crisis, and having undergone some really painful employment cuts, many companies opted to delay new hiring as long as possible, seeking to ensure that the recovery in their sales and order books was for real. Now, the logic goes, they're playing catchup.

Either of the first two explanations would be quite benign and wouldn't raise any substantive longer-term issues.

A third and more troubling possibility, though, has to do with a combination of cyclical and secular headwinds. It’s about aging infrastructure, a struggling middle class and waning productivity growth, together with Congress' blunt approach to budget management, conspiring to erode the economy's ability to grow.

In the absence of major policy modifications, these headwinds will persist — and could ultimately undermine the business confidence needed to keep creating jobs and, critically, start pushing up wages, which have been growing far too slowly.

The result would be increased income inequality, together with spreading poverty and an even weaker middle class.

Fortunately, countries can alter both their growth and employment trajectories. Just look at what Germany did at the beginning of this century, transforming itself from the “sick” economy of Europe to a relative growth and jobs powerhouse.

Rather than be lulled into complacency by benign explanations for the divergence in jobs and growth, policy makers must recognize the risk it poses to our still-incomplete recovery from the global financial crisis and the great recession that followed.

Just think of what the American economy could achieve if the beneficial impact of its energy revolution were to be turbocharged by measures to enhance competitiveness, reinvigorate the industrial sector, strengthen its human capital and implement budgetary reforms.

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