Endogenous Growth and Government Debt
Endogenous Growth and Government Debt
复制标题
内生增长和政府债务
DOI：
10.2307/1060379
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
I. King
中科院分区：
文献类型：
--
作者：
I. King
考虑到支出和税收的特定路径，永续债务融资政策的可行性多年来一直受到质疑。萨金特和华莱士[17]认为，从债务/国民生产总值比率爆炸式增长的意义上讲，这样的政策是不可行的。麦卡勒姆[8]和达比[2]认为，只有当国民生产总值的长期增长率超过税后实际利率时，这项政策才是可行的。这一特殊条件是在李嘉图等价的假设下推导出来的，在李嘉图等价的假设下，国民生产总值增长率和利率是外生给定的，不受债务路径的影响。米勒和萨金特[9]和韦尔[20]指出，一旦李嘉图等价性的假设被放弃，那么简单的长期增长率和利率的比较不足以确定稳定性。梯若尔[19]和奥康奈尔和泽尔德斯[10]在戴蒙德的[3]模型中证明了，当且仅当经济在没有债务的情况下动态低效时，这样的庞氏博弈是可行的。所有这些研究都假设GNP的长期增长率是外生给定的。在没有李嘉图等价的情况下，这一假设尤其有力。在另一篇文献中，新一代均衡增长模型最近被开发出来，在长期均衡中具有正的持续增长。在这些模型中，长期增长是由内生决定的，而不是作为某种外生给定的过程强加给模型的[7；11；12；14；15]1所有这些模型都找到了某种方法，将按规模递增的回报引入新古典增长模型，同时又保留了它可以被解释为分散均衡的事实。本文考虑了在国民生产总值增长率由内生决定且是债务水平函数的经济中，永续债务融资的可行性。这里提出的内生增长模型是普雷斯科特和博伊德[12]中给出的模型的修正版本。选择这种特殊的模式有两个原因。首先，代理人的寿命是有限的；因此，李嘉图等价一般不会在这个模型中成立。此外，生产函数在资本存量中是线性的；正如下面将变得清楚的那样，这意味着状态变量的平衡路径可以被表征为一阶线性差分方程组。
The feasibility of the policy of perpetual debt financing, given a particular path for expenditures and taxation, has been questioned over the years. Sargent and Wallace [17] argue that such a policy is not feasible in the sense that the debt/GNP ratio will explode. McCallum [8] and Darby [2] argue that this policy will be feasible if and only if the long-run growth rate of GNP exceeds the after-tax real interest rate. This particular condition was derived under the assumption of Ricardian equivalence, where the growth rate of GNP and the interest rate are exogenously given, and are not affected by the path of debt. Miller and Sargent [9] and Weil [20] make the point that once the assumption of Ricardian equivalence is dropped, then simple comparisons of long-run growth rates and interest rates are not sufficient to determine stability. Tirole [19] and O'Connell and Zeldes [10] demonstrate in Diamond's [3] model, without Ricardian equivalence, that Ponzi games such as this are feasible if and only if the economy is dynamically inefficient without debt. All of these studies assume that the long-run growth rate of GNP is exogenously given. This assumption is particularly strong in the absence of Ricardian equivalence. In a separate literature, a new generation of equilibrium growth models has recently been developed with positive sustained growth in the long-run equilibrium. In these models, long-run growth is endogenously determined, rather than being imposed on the model as some exogenously given process [7; 11; 12; 14; 15].1 All of these models find some way of introducing increasing returns to scale into the neoclassical growth model and yet preserving the fact that it can be interpreted as a decentralized equilibrium. This paper considers the feasibility of perpetual debt financing in an economy where the growth rate of GNP is endogenously determined and is a function of debt levels. The model of endogenous growth presented here is a modified version of the one given in Prescott and Boyd [12]. This particular model is chosen for two reasons. First, agents live for finite lengths of time; so Ricardian equivalence will not hold, in general, in this model. Also, the production function is linear in the capital stock; as will become clear below, this implies that the equilibrium paths of the state variables can be characterized as first order linear difference equations.