The basis of modern economics as an academic discipline -much of the substance of the textbooks that inform first-year students - was shaped by intellectual leaders, like Alfred Marshall, who believed that the scientific foundation of economics and its social impact are enhanced by grounding analysis in the practical experience of industry:
"Nearly half a century has passed since I set myself the task to obtain some insight into industrial problems by obtaining leave to visit one or more representative works in each chief industry. I tried to get such a knowledge of mechanical technique...as would enable me to understand the resources and the mode of operation of all elementary plant in general use: I sought also to study the relations between technique and the conditions of employment for men and for women." - Alfred Marshall (1919)
In 1903, Marshall established the Economics Tripos as an independent course of study at Cambridge University, England. His career began in the mid-19th century and spanned a period of more than fifty years. The importance of his theoretical contributions is evidenced by the fact that a very substantial amount of the course content for introductory economics today relies on Marshall's work.
In the preface to one of his last publications, Industry and Trade (1919), Marshall explains that he had a career-long practice of visiting manufacturing plants so that he might be better informed by the experience. This practice was motivated by the belief that his scholarly contributions would be more meaningful because of the knowledge gained in those plant visits.
Arthur Pigou, Marshall's student and successor as Professor of Political Economy at Cambridge University, confirmed this idea. Reflecting in his Memorials of Alfred Marshall, Pigou explains "What he [Marshall] aimed at in all of this was to get, as it were, the direct feel of the economic world, something more intimate than can be obtained from merely reading descriptions, something that should enable one, with sure instinct, to set things in their true scale of importance, and not to put in the forefront something that is really secondary merely because it presents a curious problem for analysis."