richardgu26 发表于 2013-12-23 08:42
Dynare里要实现ZLB有两种方式,一种是用deterministic determination, 即simul()这个命令。另一种形式就是 ...
谢谢,我去tao zha的matlab library查看了,你所推荐的内容是"Minimal State Variable Solutions to Markov-switching Rational Expectations Models" 这篇文章里面的code吗?听你这么说,或许我没办法在dynare下对一个stochatic模型施加ZLB了,除非借助其他编程软件,感谢你的答疑。
另外我想请教一个问题,在Gertler和karadi的这篇文章中,他们构造了的一个关于“news”的shock,原文是这样的:《 a model of unconventional monetary policy"
“In particular, suppose the economy is hit with news that a capital shock is likely to hit the economy in the subsequent period with probability σ. The expected size and duration of the shock (σ times the realization of the shock in each of the subsequent periods) is the same in magnitude as the shock considered in the previous experiments. Suppose further that shock is never actually realized but that for a number of periods the private sector continues to believe it will arise with probability σ. After a point it begins to revise down the likelihood of the shock. In this case, the news will reduce asset values, but because the shock is never realized, there is not a direct impact on the effect quantity of capital. Thus, we can disentangle the ”asset value” effect from the physical quantity of capital effect.
The experiment we consider proceeds as follows. We suppose the economy begins with the capital stock five percent above steady state (due perhaps to past ”overoptimism” about the returns to investment). A wave of pessimism then sets in. For four straight quarters the private sector believes a capital quality shock will hit that is in expected value of the same magnitude as the autoregressive shock considered in the previous section. After the shock is not realized, the private sector then revises down the likelihood by a factor of .5 each period.”
简而言之是人们预期到一个news shock to the economy,而这种预期会引起资产价格的波动,而实际上这种shock在后面并没有发生,只是这种pessimistic 的情绪还存在,人们降低了对这种shock的发生的主观概率。我想请问一下,在dynare中可以如何去构建这样一个shock了?对于文中表述的shock发生的主观概率,我并不是很了解如何在dynare中实现。
很抱歉,问你的问题有些长,如果你有空的话,请给予你的建议看法,非常感谢。