The primary purpose of this research is to analyze theoretically the group decisionmaking process leading to the allocation of activity time and the consumption of goods, with particular emphasis in the households. Each household is characterized as a group of individuals making joint decisions about their activity participations, alternative activity time allocations and consumption of various goods, such as independent and joint activity time allocations as well as private and shared consumption patterns. We firstly explore why individual-based models are not realistic in multi-person households, and secondly, we summarize various intra-household activity time allocation models based on different decision-making processes. All models are presented under microeconomic principle of utility maximization to represent the economic behavior of the households.