That gap between the official estimate and mine is significant.

FORBES: Magazine Article

The HMRC's estimate of the alcohol tax gap was published most recently in September 2011.

BBC: Bottles

Earlier this year, staff at the Federal Reserve also marked down their estimate of the country's potential GDP and the output gap in response to the surprisingly steep drop in unemployment.

ECONOMIST: Free exchange

We also thought they would probably cut or leave unchanged their estimate of spare capacity in the economy (the "output gap") - again, on the basis of their calculations in March.

BBC: The Bank, the OBR and Mr Osborne

They estimate that it will not return to that level until the first half of 2015 - a gap of seven years.

BBC: UK GDP: Economy shrank at end of 2012

In the absence of any official estimate of the size of the stimulus, market-watchers looked for an unofficial figure to fill the gap.

ECONOMIST: The slowing economy