Knowledge that Transforms

Recent estimates of the potential growth effects of tax reform vary wildly, ranging from zero to eight percentage points. Using an endogenous growth model, the authors assess which model features and parameter values are important for determining the quantitative impact of tax reform. The quantitative estimates in several recent papers are compared with each other and with some of the evidence from U.S. experience. The authors find that Robert Lucas's conclusion, that tax reform would have little or no impact on the U.S. growth rate, is theoretically robust and consistent with the evidence.

This paper addresses the issue of credibility from an econometric perspective. It develops a rational expectations model of inflation in which the dynamics are driven by the level of government spending and by the effect of past inflation rates on the value of real taxes. Government expenditure is modeled as an exogenous autoregressive process subject to discrete changes in regime. The regimes are defined by whether the level of spending is or is not consistent with the rate of inflation targeted by the government as part of a stabilization program. In making their money demand decision, the agents need to construct probability inferences regarding the state of the expenditure process. Credibility is quantified by the agents' inferred probability that the joint observation of inflation, the nominal interest rate, and government spending is generated by the reformed expenditure regime. In an application to Israel, results indicate that the failed stabilization program of November 1984 was less than fully credible to the agents. The uncertainty about the true nature of the expenditure process partially explains the volatility of the rate of inflation in this period. In contrast, for the July 1985 program the agents correctly inferred a change in the regime driving the government spending process.