Monetary policy decisions tend to be based on systematic analysis of alternative policy choices and their associated macroeconomic impacts: this is science. Fiscal policy choices, in contrast, spring from unsystematic speculation, grounded more in politics than economics: this is alchemy. In normal times, fiscal alchemy poses no insurmountable problems for monetary policy because fiscal expectations can be extrapolated from past fiscal behavior. But normal times may be coming to an end: aging populations are causing promised government old-age benefits to grow relentlessly and many governments have no plans for financing the benefits. In this era of fiscal stress, fiscal expectations are unanchored and fiscal alchemy creates unnecessary uncertainty and can undermine the ability of monetary policy to control inflation and influence real economic activity in the usual ways.

International Monetary Fund The impact of fiscal stimulus depends not only on short-term tax and spending policies, but also on expectations about offsetting measures in the future. This paper analyzes the effects of an increase in government spending under a plausible debt-stabilizing policy that systematically reduces spending below trend over time, in response to rising public liabilities. Accounting for such spending reversals brings an otherwise standard new Keynesian model in line with the stylized facts of fiscal transmission, including the crowding-in of consumption and the ‘puzzle ’ of real exchange rate depreciation. Time series evidence for the U.S. supports the empirical relevance of endogenous spending reversals. Keywords: JEL-Codes: Fiscal policy transmission, consumption, real exchange rate,