Transformational technologies are exciting, but inspiration alone will not beat government spending cuts, bank lending squeezes and overcapacity.

Despite starting 2011 on a wave of (slightly misplaced) optimism, the world economy grew at about 3% last year — much less than expected.

The inventory restocking that had driven growth 12 months earlier started to wear off as governments tightened monetary policy. The gloom was worsened by a series of shocks.