Policy Announcements and Welfare
研究发现政策制定者提前公布未保险的宏观风险会扭曲家庭保险机会，增加消费分配方差，降低事前福利；在货币政策中，提前公布通胀目标可能因企业定价调整而损害福利，但若存在家庭异质性风险，央行保持秘密可能更好。
In this paper we show that policy announcements can be detrimental to social welfare. We consider an economy in which agents face idiosyncratic and aggregate risk. The policy maker learns about the aggregate shock before it directly impacts on the allocation, and can decide to announce that information early. Households partially insure the idiosyncratic risk in contracts consistent with voluntary participation incentives. By announcing the non-insurable risk early, the policy maker distorts agents ’ insurance possibilities, thereby increasing the variance of the optimal consumption allocation and worsening welfare ex-ante. As a particular application, we consider the problem of a monetary authority, which has the option of announcing shifts in the inflation target early. In this economy, monetary policy has real effects captured by a cash-in advance constraint. A fraction of firms need to set prices one period in advance, so that a late announcement of inflation targets induces welfare-reducing distortions of relative prices, if no idiosyncratic risk is present. However, with idiosyncratic risk of households – modeled as employment opportunities – we show that it may be better for the central bank to remain secretive.