This thesis studies an economy (without growth) populated by overlapping generations of rich and poor agents, with the difference between them being that the rich are endowed with larger amounts of wealth in both period. Both types of agents want to transfer wealth over time and smooth out their consumptions. Agents could borrow from or lend to each other in credit market, when borrowing they are subject to a collateral constraint. Agents could also buy house(s), which are indivisible and pay no dividend whatsoever. Because of the lack of investment instruments and dynamic inefficiency in bubble-free steady states, a rational housing bubble could arise. Due to its high prices and indivisibility, houses are not affordable to the poor. So in ...