Markets for commodities such as wheat, crude oil, or pork bellies depend on the ability to measure quantity, whether it be in bushels, barrels, or tons. On the other hand information-rich commodities such as books or newspapers are priced per unit rather than by such measures as volume (despite apocryphal stories of assessing dissertations by weight), since they are always bought and sold whole, and there is little point in trying to establish a price for half a book, or a fraction of a newspaper. Similarly paper maps are priced by unit, rather than by square kilometer or some other continuous-scaled measure.
Stored only when both papers are in the corpus — 15 citations exist upstream.
Imported from OpenAlex (CC0) — nothing here is generated.