非貿易財模型與政策搭配問題

THE ASSIGNMENT PROBLEM FOR A SMALL OPEN ECONOMY WITH NONTRADED GOODS

本文建構非貿易財模型分析政府與中央銀行之間的政策搭配問題，兩個政策目標分別為物價穩定（內部均衡）以及貿易平衡（外部均衡）。理論模型指出政府對非貿易財支出的總合政府支出彈性在政策搭配問題中扮演重要角色。若政府對非貿易財支出的總合政府支出彈性相對小，則應以貨幣政策維持外部均衡，而以財政政策維持內部均衡（法則一）;反之，若以貨幣政策維持內部均衡，而以財政政策維持外部均衡（法則二），則將造成動態的不安定。我們更發現，若政府對非貿易財支出的總合政府支出彈性相對大，導致政府實施擴張性財政政策引發貿易帳餘額增加，則兩種法則皆滿足動態安定性。我們以此強調政府應該增加對非貿易財的支出，從而增加政策搭配上的彈性。

This paper develops a nontraded goods model to analyze the assignment problem of how the government and central bank cooperate. The policy goals are price stability (internal balance) and trade balance (external balance). Our model shows that the aggregate government expenditure elasticity of government expenditure on nontraded goods is a critical variable parameter for the assignment problem. If the aggregate government expenditure elasticity of government expenditure on nontraded goods is low, the central bank should secure the external balance and the government should secure the internal balance (Rule I). It is unstable if the central bank secures the internal balance, and the government secures the external balance (Rule II). Moreover, if the aggregate government expenditure elasticity of government expenditure on nontraded goods is high, such that an increase in aggregate government expenditure leads to a rise in the trade balance, then both rules are stable. We conclude the government should increase spending on non-tradable goods to increase the flexibility of the policy assignment.