Furthermore, debt management policies can be all the more effective in the special case of the zero lower bound (ZLB). This is because policies aimed at shortening the duration of debt held by the public (ie selling Treasury bills and buying government bonds) may lower long-term yields without raising short-term yields, which are glued close to zero at the ZLB. But note that the corollary of the ZLB argument on its own is a policy asymmetry. Central banks may need to buy government bonds when at the ZLB if they want to stimulate demand. But they have no need to.
