On Friday, May 18, the Commerce Department issued its annual revisions to manufacturer shipments. The revisions reached back all the way to 2001, with minor revisions to seasonality and little change to annual shipments. Starting with 2009, however, there were significant downward revisions. On a current-dollar basis, 2009 was revised down by $942 million, with the total year at $82.9 billion; 2009 data had been revised down in last year's update as well. For 2010, shipments were revised down by $1.56 billion, with annual shipments at $82.5 billion. Shipments for 2011 were revised down by $1.76 billion, bringing industry shipments to $81.6 billion. Surprisingly, even shipments for the first quarter or 2012 were revised down significantly, by $600 million. This means that the Commerce Department has been overestimating shipments by $200 million per month just for this year. The chart below shows the nature of the revisions in graphic form for the inflation-adjusted data series (click to enlarge). The revisions to the data series have also affected the forecasting models we use to show steeper future declines. These will be discussed in future columns and in our annual special report about historical printing shipments. There are often questions about how these data relate to those published by industry trade associations. That topic is discussed in detail in our Slideshare podcast from last December which includes a discussion about the inflation adjustment and its effects on market size estimation, business decisions, and future forecasts.