MANY dour writers have already christened the decade to 2009 a lost one, based on the more or less flat performance of the median household income over that time. Increasingly, economists are suggesting that there may be another decade yet where that came from.

Not long ago, researchers at the Kansas City Fed wrote a paper (PDF) comparing past recessions in America and other rich countries with a particular emphasis on the labour market experience in recessions that occur with financial crises. Perhaps unsurprisingly, they find that employment declines are deeper in crisis-led recessions and recoveries take significantly longer. Based on 1) the severity of the current American recession and the associated crisis, 2) the distressingly rapid rise in the unemployment rate, and 3) the fact that labour market recoveries have taken longer in recent recessions, the authors conclude that the unemployment rate may stay elevated for a decade or more. They envisage scenarios in which unemployment may not dip below 7% until 2016.

Now, Stephen Greenhouse, writing at the New York Times, notes that a pair of economists at Rutgers are suggesting the labour market may not fully recover until 2017. They point out that in the decade to 2001 (for many a very prosperous period) the American economy added around 2.15 million jobs per year, on average. Applying that rate to the current labour force (which may be too bold given that from 2001 to 2007 only 1 million jobs were created per year), the economy will finally work off its job deficit in late 2017.

This is troubling stuff. It is a rare economic expansion that persists for a full 8 years, which means that by the time labour markets are approaching full employment, the business cycle will have once again turned to contraction. It will be difficult for worker wages to rise with so much persistent slack in the system for so long. The distressing conclusion seems sure to be that incomes for many workers will stagnate, more or less permanently.

That's an extremely pessimistic forecast. I don't know that I can bring myself to believe it; the American economy is quite resilient, and the progress of technology continues, constantly creating new growth industries which might one day employ millions of people. Still, it has been a long time since the American job engine really hummed. Concern, at any rate, is certainly warranted.