An extension of a Yaari (1965)- Blanchard (1985) continuous time overlapping generations model for an endowment Arrow-Debreu economy with an age-structured population is presented. It is proved that Arrow-Debreu equilibrium prices are represented bya double linear integral equation, and depend on the age-distribution of population and endowments. For an economy with a balanced growth, and logarithmic utility, we prove that bubbles may exist if endowments are distributed earlier than some critical age.