It is possible to view econometric history as the retrospective assessment of intellectual resource allocations+ This paper uses such a perspective to examine the history of extraneous estimation+ Independently proposed by Marschak~1939, Econometrica 7, 332-335! and Wold~1940, Efterfrågan på jordbruksprodukter och dess känslighet för prisoch inkomstförändringar~The demand for agricultural products and its sensitivity to price and income changes!!, extraneous estimation was widely used as a collinearity solution in demand analysis from 1950 to 1980+ We give a detailed account of the origins of this procedure and the theoretical work that clarified the statistical structure that underpinned it+ The subsequent literature is then assessed in terms of the optimal use of available econometric tools and the interaction between theory and applications+ We find that optimal econometric procedures were rarely used and that theoretical refinements continued to be published well after extraneous estimation had ceased to be a useful tool for demand analysis+