It is a rejection of postitivism[?] within economics(see also Methodenstreit).
External Links
Human Action by Ludwig von Mises (http://www.mises.org/humanaction.asp)
... household size is 2.47 and the average family size is 3.07. In the town the population is spread out with 22.3% under the age of 18, 6.7% from 18 to 24, 28.0% from 25 ...