Business Inventories, or Manufacturing and Trade Sales and Inventories, show a 1.2% increase in sales but only a 0.2% increase in inventories in comparison to October. Earlier, wholesale inventories, about a third of all inventories, also showed a deceleration in growth.
Below is the monthly percent change for business inventories. Inventories have been a large part of GDP. They are annualized, quarterly. This report is only part of the total inventories in the U.S.
Assuming there is zero percent change from November to December in business inventories implies the percentage change contribution of private inventories to Q4 GDP would be 7.41%. This is in comparison to a Q3 11.6% annualized growth rate in business inventories. In Q3 2010, the changes in inventories 63.1% of total GDP growth.
On the other hand, PCE, or personal consumption increased for Q4 2010 with the current estimate being at least a 4% growth contribution to GDP from personal consumption. This is much higher than the third quarter, where PCE was 2.4% of an increase. To see the actual equations used to create these estimates click here.
This Census economic report covers Retail, Manufacturing and Wholesale inventories, which is pretty much most of the non-farm inventories the BEA uses for their change in private inventory calculations in the GDP report and national accounts.
This gives a reasonable guesstimate that changes in private inventories will not be contributing nearly as much to Q4 GDP growth.