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)
... together, 11.9% have a female householder with no husband present, and 42.6% are non-families. 36.3% of all households are made up of individuals and 17.6% have someone ...