Further criticism related with one of main assumptions based on the public choice theory which is related to the concept, "methodological individualism" which assumes that people act rationally, always pursue their own economic self interests and will make optimal economic choices in order to achieve their self interests. However this assumption may be undermined when the unit of residence is not an individual but a family. Related to this point Stanyer (1980 cited in Smith: 1985) argues that the preferences of a family may not be the same as an individual of the family which may be created by lot of compromises between family members. So that any decision to relocate a family will not maximize the utilities of all its members, argues the author.