Abstract: | This paper discusses the theory and measurement of information externalities in oil and gas leasing. A study of leases issued in the Gulf of Mexico reveals significant positive information externalities resulting from prior development of adjoining leases. According to a recent court decision, these effects provide an added consideration in the determination of a "fair and equitable" division of revenues from federal tracts adjoining state lands, as required by the 1978 amendments to the Outer Continental Shelf Lands Act |