The U.S. Census Bureau announced today that advance estimates of U.S. retail and food services sales for February, adjusted for seasonal variation and holiday and trading-day differences, but not for price changes, were $355.5 billion, an increase of 0.3 percent (±0.5%)* from the previous month and 3.9 percent (±0.5%) above February 2009. Total sales for the December 2009 through February 2010 period were up 4.5 percent (±0.3%) from the same period a year ago. The December 2009 to January 2010 percent change was revised from +0.5 percent (±0.5%)* to +0.1 percent (±0.3%)*.
When your figures are off by say up to 30% people don't raise too many eyebrows, but when you've blown it by several hundred percent, methodology has to come into question.