财政约束与价格水平决定:FTPL的一个批判

Fiscal Budget Constraint and The Determination of Price Level:A Critique on FTPL

本文在一个内生增长一般均衡货币模型中, 通过引入名义债券、实际债券、货币和物质资本, 讨论了政府财政约束与价格水平决定的关系。我们发现, 在平衡增长路径上均衡通货膨胀率完全由货币增长率决定, 政府跨时预算约束方程只是个恒等式。如果价格水平财政理论(FiscalTheoryofPriceLevel, FTPL) 成立, 则小得可以忽略的财政扰动可以导致物价水平的巨大波动, 这是无法让人接受的; 进一步的研究发现, 问题出现的原因是FTPL将名义债券市场和其他资产市场割裂开来, 孤立地讨论了名义债券市场出清的条件, 由此认为跨时预算约束方程是一个均衡定价方程; 当将诸市场统一起来考虑时, 公众可以在货币、债券和物质资本之间进行选择, 财政当局不再是一个价格决定者, 其债券发行量成为一个内生变量, 必须服从跨时预算约束方程, 后者成为一个恒等式, 从而价格水平主要由货币当局的货币发行决定。

The relationship between government's fiscal budget constraint and determination of price level is discussed in an endogenous growth general equilibrium model. We show that inflation rate is determined by the growth rate of money completely on the balanced growth path, and the government's intertemporal budget constraint is an identity. Under the Fiscal Theory of the Price Level (FTPL), we can get an unacceptable result in which a nominal bonds' negligible change can cause very large variation of the price level. We find that FTPL separates nominal bonds market and other assets market and only considers the nominal bonds' market clearing condition. If we put these asset markets together then individuals can make choices between all assets. Thus government's intertemporal budget constraint cannot be an equilibrium evaluation equation and fiscal authority cannot be a price maker. Therefore the issues of nominal bonds must be an endogenous variable and the price level is mainly determined by the central bank.