The ratio of the weight of localized materials used in the manufacture of a product to the weight of the finished product. A material index much greater than 1 shows a sizeable weight loss during manufacturing. For many resource-based manufacturing activities where inputs are more expensive to transport than the final product, production will normally be drawn to the source of the material input (Polèse and Shearmur (2004) Int. Reg. Sci. Rev. 27, 431).
Subjects: Earth Sciences and Geography.