form a joint household by adopting a sharing rule (θ) that determines the relative weight each
individual’s preferences will receive in the joint household. Thus, the household’s utility
function is a weighted sum of the utility functions of the individuals in the household:
(1) Uh = θ Ui + (1-θ) U2
The sharing rule has many possible components. It may be based upon individual beliefs,
social norms, or the relative power of each household member. Economists have tended to
place greater emphasis on power, while sociologists have been more open to recognizing
individual beliefs and social norms. There is, however, much overlap.
Economic „power’ can be captured along several dimensions. Relative earnings
ability may be important because individuals with higher earnings potential have the
capability of bringing more resources to the household. This ability may give them the power
to allocate a greater share of household resources. Similarly, from the bargaining literature,
individuals with greater earnings potential may have more power because they are likely to
have a higher utility operating as independent units. Such individuals may need additional
incentives (such as a higher θ) to induce them to enter into and remain in a joint household.
Sociologists similarly view the unequal division of power within the household as reflecting
the „dependency „of women on their husbands (S0rensen and McLanahan 1987, Bittman et al
2003).
Several approaches to the empirical measurement of such power have developed. A
number of studies compare annual earnings (for example Geist 2005, Fuwa 2004, Bittman et
al 2003) typically with controls for time employed by both partners. Others use wages (for
example Chiappori, Fortin, LaCroix 2002; Van Der Lippe and Siegers 1994). Pollak (2005)