英国索尔福德作业代写:罗伯特·卢卡斯
Keywords:英国索尔福德作业代写
另一个重要的发展是由罗伯特·卢卡斯在他的1976篇论文，计量经济政策评估：一个批评。在本文中，他开发了一个模型，企业拥有的价格水平只有不完善的信息。假设他们知道他们的价格在他们自己的市场，但不是一般的价格水平。公司的问题如下。如果价格在他们自己的市场增加，那么他们将要增加产量响应。如果一般价格水平增加，那么他们就不想改变他们的输出。问题是，当观察到价格变动时，公司不知道这种变化是否代表了市场需求的变化，价格水平的变化或两者的结合。只有在下一个时期，公司才了解到上一个时期的物价总水平。这里有许多重要的含义。第一，如果政府的通胀是意外的，只有产出反应才会出现。另一个重要的含义是，代理商可以学习。如果他们观察到当局创造了通货膨胀来操纵需求，他们就不会改变他们的产出来应对价格变化；即使是在他们自己的市场价格的变化，这需要一个输出响应。这里的含义是，如果政府希望控制失业，应寻求供应方的政策，并尽量保持总物价水平不变。更普遍的含义是，试图操纵一个历史的关系，以实现政策目标将无法工作，因为关系的参数是预期的功能，这反过来又受到影响，试图实现政策目标。
英国索尔福德作业代写:罗伯特·卢卡斯
Another important development was introduced in a paper by Robert Lucas in his 1976 paper, Econometric Policy Evaluation: A Critique. In this paper he developed a model where firms possessed only imperfect information about the price level. The assumption was that they knew the price their good fetched in their own market but not the general price level. The problem for the firm is as follows. If the price in their own market increases then they will want to increase output in response to it. If the general price level increases then they will not want to alter their output at all. The problem is that when a movement in price is observed, the firm does not know if the change represents a shift in demand in their market, a change in the general price level or a combination of the two. It is only in the next time period that the firm learns what the general price level was in the previous period. There are a number of important implications here. The first is that there will only be an output response if the inflation created by the government is unexpected. The other important implication is that agents can learn. If they observe the authorities creating inflation to manipulate demand they will not change their output in response to a price change; even if it is a change in the price in their own market which requires an output response. The implication here is that if the government wishes to control unemployment it should pursue supply side policies and try to keep the aggregate price level constant. The more general implication is that trying to manipulate a historical relationship to achieve a policy objective will not work, since the parameters of the relationship are functions of the expectations which are, in turn, affected by the attempt to achieve the policy objective.
