As discussed in Hulten (1979) [. . .] this [. . .] has an important implication for the treatment of
intangible capital: any use of resources that reduces current consumption in order to increase
it in the future qualifies as an investment. This result argues for symmetric treatment of all
types of capital, so that, for example, spending on R&D and employee training should be
placed on the same footing as spending on plant and equipment. Moreover, this symmetry
principle requires that most business expenditures aimed at enhancing the value of a firm and
improving its products, including human capital development as well as R&D, be accorded
the same treatment as tangible capital in national accounting systems (Corrado et al., 2006,
p. 9, present authors’ italics).