In summary, the policy conclusion is that in an environment with asset shortages, it is important to recognize that speculative valuations are part of the equilibrium. In this context, the best policy is to minimize the resource misallocation they may cause and to protect their stability. The latter can be achieved by fostering the spreading of the aggregate bubble across many assets (i.e., foster an extensive rather than an intensive margin), by not chasing them indiscriminately, and by providing some sort of implicit or explicit backing to some of the speculative assets. The good news is that in a world of low interest rates, even a pledge of a small share of the tax receipts can back a large amount of assets, as long as the total revenue from these taxes grows in tandem with the economy.