Evaluating Estimates of Materials Offshoring from U.S. Manufacturing
When materials offshoring is measured by estimating imported intermediate inputs, a common assumption used is that an industry's imports of each input, relative to its total demand, is the same as the economy-wide imports relative to total demand: this is the so-called "import comparability" or "proportionality" assumption. A report to the National Research Council identified this assumption as being a significant limitation of current data collection and analysis. In this note we move beyond this assumption to obtain a direct measure of imported materials by industry for the United States in 1997. At the 3-digit I-O industry level, there is a correlation of 0.68 between the offshoring shares made with and without the proportionality assumption, and a higher correlation of 0.87 when the shares are value weighted. While most value-weighted industry have differences below 50 percentage points in the two estimates, there is significant number of cases that differ by 10 percentage points or more.
Published Versions
Feenstra, Robert C. & Jensen, J. Bradford, 2012. "Evaluating estimates of materials offshoring from US manufacturing," Economics Letters, Elsevier, vol. 117(1), pages 170-173. citation courtesy of