Long-Term Debt and Optimal Policy in the Fiscal Theory of the Price Level
研究财政价格水平理论中，长期债务的期限结构如何影响通胀动态，并求解最优债务政策以最小化通胀波动，发现长期债务有助于稳定通胀，且最优政策产生的数据序列与美国实际数据相似。
The fiscal theory says that the price level is determined by the ratio of nominal debt to the present value of real primary surpluses. I analyze long-term debt and optimal policy in the fiscal theory. I find that the maturity structure of the debt matters. For example, it determines whether news of future deficits implies current inflation or future inflation. When long-term debt is present, the government can trade current inflation for future inflation by debt operations; this tradeoff is not present if the government rolls over short-term debt. The maturity structure of outstanding debt acts as a ‘‘budget constraint’’ determining which periods’ price levels the government can affect by debt variation alone. In addition, debt policythe expected pattern of future state-contingent debt sales, repurchases and redemptionsmatters crucially for the effects of a debt operation. I solve for optimal debt policies to minimize the variance of inflation. I find cases in which long-term debt helps to stabilize inflation. I also find that the optimal policy produces time series that are similar to U.S. surplus and debt time series. To understand the data, I must assume that debt policy offsets the inflationary impact of cyclical surplus shocks, rather than causing price level disturbances by policy-induced shocks. Shifting the objective from price level variance to inflation variance, the optimal policy produces much less volatile inflation at the cost of a unit root in the price level; this is consistent with the stabilization of U.S. inflation after the gold standard was abandoned.