在次級房貸風暴之後，各國赤字大幅增加。如希臘與愛爾蘭，其主權債務違約風險皆大幅升高。面對這樣的困境，政府該如何實施財政政策，以防止主權債務危機的發生?本篇文章在DSGE模型之下，以Uribe(2006)的設定為基礎架構，額外增加了產出方程式以使國家產出能由模型內生決定。並加入了政府支出與產出之間的關係式，以討論在面對正的景氣衝擊與負的景氣衝擊時，政府使用正向景氣循環政策和負向景氣循環政策對於政府倒債率的影響。最後發現當政府使用負向景氣循環政策和較弱的順向景氣循環政策時，政府的倒債率會和技術衝擊有反向的關係。而當政府使用較強的順向景氣循環政策時，政府的倒債率會和技術衝擊有正向的關係。從此結果，我們推論在後金融海嘯時期，希臘與愛爾蘭等國家，應使用較強的順景氣循環政策以降低其主權債務危機的發生機率。 / After the subprime crisis, many government deficits rose sharply, especially Greece and Ireland. Their default rate rose greatly than before. Under this difficult situation, what kind of fiscal policy should the government enforces to prevent it from bankruptcy? We follow the model in Uribe (2006) as our framework but adding the production function and the government expenditure function to analyze the effects of different fiscal policies on the government default rate. The results tell us that when the government uses countercyclical fiscal policy and weak procyclical fiscal policy, the change of the default rate is opposite to the technical shock. On the contrary, when the government uses strong procyclical fiscal policy, the default rate is positive relation with the technical shock. This implies that governments, such as Greece and Ireland, should use strong procyclical fiscal policy to reduce their sovereign risk under the recession.

在一兩開放體系為貨幣同盟與非貨幣同盟的情況下， 本文利用微分賽局理論來探討兩對稱國政府在財政政策上的策略搭配。 本研究分析並比較兩國在貨幣同盟國與非貨幣同盟國中採取合作的財政政策、非合作的財政政策與領導和跟隨者的財政政策等三種不同策略對兩國總體經濟之影響。 最後本文對本研究的模型作數值模擬並試圖利用其結果來闡明目前歐元區國家主權債務危機的可能解決之道。 / Considering both cases of monetary union and non-monetary union, this paper uses the differential game theory to explore the coordination of the fiscal policies between two governments. In both cases, each country can choose to cooperate in the fiscal policy, not to cooperate in the fiscal policy, or just to follow the policy of the other country. Diffrent stratigical decisions may cause different economic impacts. Finally, the paper also uses numerical method to simulate our model and provide some possible solutions to the current economic crisis of the Eurozone.