平衡預算法則、功能性政府支出與總體經濟（不）安定性──消費稅的角色

BALANCED-BUDGET RULE, USEFUL GOVERNMENT SPENDING AND MACROECONOMIC (IN)STABILITY: THE ROLE OF CONSUMPTION TAXES

本文將校廢稅引入Guo and Harrison（2008）的模型，以重新檢視預期兌現（或非唯一性）的條件。我們發現政府支出僅由消費稅融通時，不管內生的政府支出功能性為何，樂觀預期皆可能不兌現，此時政府支出的功能不再是主導體系安定與否的關鍵。其次，若政府支出同時由消費稅與所得稅融通，則消費稅會讓樂觀預期不易兌現，亦即消費稅有安定體系的功能。最後，稅制本身可能才是主導樂觀預期兌現與否的關鍵而非政府支出的功能。

By introducing consumption taxes into the model of Guo and Harrison (2008), this article reexamines the conditions of self-fulfilled expectation (or indeterminacy). We find that in spite of productive government spending (productivity-enhancing) or public consumption spending (utility-enhancing), self-fulfilled expectation may not exist if the spending is only financed by consumption taxes. In addition, consumption taxes lead to indeterminacy equilibrium not easily if government spending is financed by both income taxes and consumption taxes. In other word, consumption taxes have stabilized function on business fluctuation. Finally, the key factor that results in self-fulfilled expectation may be the taxes system itself but not the use of government spending.