However, the mixed signals are still an improvement over the almost uniformly negative tone of the markets for nonresidential structures a year or two ago. To me, they suggest that the nascent upturn in this sector is likely to continue. Inventory investment So far I have discussed business fixed investment. Another important part of capital expenditures, however, is inventory investment.
There are three types of inventory investment: materials and supplies, work in progress, and finished goods. In dollar terms, inventory investment is not large: From 1994 to 2003, it averaged about $ billion - less than 1 percent of GDP.