| 简介： | We provide a model of rational bubbles in a DNK framework. Entrepreneurs are heteroge-neous in investment efficiency and face credit constraints. They can trade bubble assets to raise their net worth. The bubble assets command a liquidity premium and can have a positive value. Monetary policy affects the conditions for the existence of a bubble, its steady-state size, and its dynamics including the initial size. The leaning-against-the-wind interest rate policy reduces bubble volatility, but could raise inflation volatility. Whether monetary policy should respond to asset bubbles depends on the particular interest rate rule and exogenous shocks. |