Even if productivity growth does tail off, it may still be strong enough to match sluggish demand.

ECONOMIST: Productivity growth

In an interview with Forbes this morning, Andreesen Horowitz partner Scott Weiss noted that the Silver Tail has seen huge growth since the firm invested in the company 18 months ago, growing from a dozen employees then to 100 now.

FORBES: EMC To Buy Silver Tail Systems; Terms Not Disclosed

As the country gets richer and its working-age population starts to shrink, that growth rate is likely to tail off to perhaps 8% soon.

ECONOMIST: Becoming number one | The

Gone are the days when quarters of growth succeeded each other nose to tail and national debt was limited by a fiscal rule to 40% of GDP.

ECONOMIST: Politics and the British budget

"After the hyper growth in the e-book market over the last few years, consumers have settled into their book formats of choice, and while e-books will continue to drive growth in the book category in the future, physical book sales will have a longer tail (or longer life expectancy) than previously anticipated, " he said in a call with investors.

WSJ: Barnes & Noble posts 3Q loss as Nook demand slows