  A dynamic model of collective consumption and saving decisions made by a
finite number of agents with constant but different discount rates is
developed. Collective utility is a weighted sum of individual utilities with
time-varying utility weights. Under standard separability assumptions, it is
shown that collective preferences may be nonstationary but still satisfy time
consistency. The assumption of time-varying weights is key to balance the need
of the group for a changing distribution of consumption among its members over
time with their tolerance for consumption fluctuations.
