The critique grows out of the basic assumption that women perform three roles – the productive, reproductive and the consumer. It has been customary to speak about the "double burden", of women, setting the work role against the domestic role. However, when the child bearing and rearing role is merged with the consumer, role under the rubric of "housewife" or domestic role, certain critical differences in the nature and duration of the two tasks are blurred. On the one hand, the periods of child-bearing and child rearing are limited, yet fixed by factors beyond a woman's control, while housekeeping is a permanent and ongoing feature. On the other hand specific housekeeping tasks may be postponed, avoided or delegated, while the child requires continuing attention and cannot be treated in the same way. So separating the two into three roles' offers greater clarity of definition.