日本政府债务可持续性问题再探讨

Re-discussion on the Issue of Japanese Government Debt Sustainability

在日本政府债务率居高不下的背景下,宽松的货币政策和私人部门高储蓄率下对于国债的巨大购买需求,支撑了日本国债收益率处于低位水平。然而,这种情形在未来难以长期持续,平衡一旦被打破,将对日本经济产生重大不利影响,甚至引起债务危机。本文通过量化模拟分析,在财政货币政策没有大幅度变动的情况下,预计日本政府债务率将在2022年左右突破"天花板",国债收益率水平将随之上升。实际情况中,如果由于政府主权债务评级、地缘政治、国外政府债务危机等因素诱发原有预期发生变化时,可能导致在政府债务率突破"天花板"之前,国债收益率突然上升。就目前而言,日本政府短期内具有一定的政策空间并采取一定措施,将政府债务率控制于"天花板"之下的安全区间。

Japanese government debt ratio stays in a high level, while its interest rate of government bond keeps in low. This is due to the great government debt demand from Japanese easy monetary policy and highly saving ratio in private sector. However, such situation is hard to keep in long term, in case the balance is broken, Japan economy will fall in dangerous, even in debt crisis. In this paper, by quantitative simulation prospect that Japanese government debt rate would break through its ceiling, and interest rate of government bond will crease at the year around 2022, with the condition of the fiscal and monetary policy keep in stable. Actually, if the expectation factors, such as Japanese sovereign rating grade, Japa- nese geopolitics and foreign government debt crises, the interest rate of Japanese government bond would increase rapidly even when the debt bellows the ceiling. As far as Japanese government should take in time to take appropriate policy measures to make the government debt ration in safe range.