The aggregate feasibility set for the economy is given by the set of all feasible allocations, which satisfy the resource constraints of the economy. This can be represented as the set of all allocations (c1, c2, ..., cT) such that:
c1 + c2 + ... + cT ≤ yNt for all t
where c1, c2, ..., cT are the consumption levels of the young individuals in each period, and Nt is the population size in period t.