国债负担率警戒线刍议

A Tentative Discussion on Public Debt Ratio

中文关键词:  国债负担率  税收平滑  非蓬齐博弈

英文关键词:public debt ratio  tax smoothing  No-Ponsi Game

中文摘要:

      从国债的起源和国债的本质出发,探讨国债偿还路径和国债负担率警戒线问题。得出的结论是:国债本质上是税收,是一种平滑税收的制度设计,能够保证代表性行为人跨时期福利的最大化;国债是政府面临非常开支增加、而该开支是对未来有利的情况下方可使用的融资形式,消费性政府开支非常规增加不应由国债筹集;只有持续的政府投资性开支能够带来长期经济增长,所以一旦采用国债为政府投资性开支融资,就必须将其持续下去,需要在还旧债的同时发新债;非蓬齐博弈准则,是对单笔国债偿还路径的不二描述;而政府用国债为投资性政府支出融资以维持经济增长时,进行的是还旧债、借新债,此时要以国债余额增长率小于等于经济增长率为准则,以保证债务负担率不提高,不必遵守非蓬齐博弈准则;债务是逐步累积的,债务负担率提高的过程是政府未来收入提高的过程,也是政府信誉提高的过程,不能不分国别统一划定最优债务负担率。

英文摘要:

      With a historical,logical and concise mathematical method,this paper analyzes the threshold of public debt ratio,which can be inferred from the nature of government debt.It concludes that government debt is the taxation in essence,one kind of mechanism to smooth tax so as to maximize the inter-temporal utility of the representative agent.When facing an unusual increase in expenditure which would be beneficial to the future,public debt would be the best option.An increase in government consumption,on the other hand,should not be supported by public debt.Since only continuous government investment can realize long-term economic growth,public-debt-issuing should also be a continuous process.The optimal path of the redemption of the government debt can be depicted by the so-called No-Ponsi Game.In the case of paying off old debts and issuing new debts at the same time,however,No-Ponsi Game is not sufficient to depict the path.The process of debt accumulation should also be the process of increasing government future revenue,and the process of increasing government credit.There is no unified threshold ratio of public debt among different countries.