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Fiscal Sustainability in a New Keynesian Model
Author(s) -
LEITH CAMPBELL,
WRENLEWIS SIMON
Publication year - 2013
Publication title -
journal of money, credit and banking
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.763
H-Index - 108
eISSN - 1538-4616
pISSN - 0022-2879
DOI - 10.1111/jmcb.12060
Subject(s) - economics , new keynesian economics , debt , fiscal policy , government debt , temptation , precommitment , monetary policy , monetary economics , debt to gdp ratio , macroeconomics , internal debt , debt levels and flows , microeconomics , social psychology , psychology
Recent work on optimal monetary and fiscal policy in New Keynesian models suggests that it is optimal to allow steady‐state debt to follow a random walk. In this paper we consider the nature of the time inconsistency involved in such a policy and its implication for discretionary policymaking. We show that governments are tempted, given inflationary expectations, to utilize their monetary and fiscal instruments in the initial period to change the ultimate debt burden they need to service. We demonstrate that this temptation is only eliminated if following shocks, the new steady‐state debt is equal to the original (efficient) debt level even though there is no explicit debt target in the government's objective function. Analytically and in a series of numerical simulations we show which instrument is used to stabilize the debt depends crucially on the degree of nominal inertia and the size of the debt stock. We also show that the welfare consequences of introducing debt are negligible for precommitment policies, but can be significant for discretionary policy. Finally, we assess the credibility of commitment policy by considering a quasi‐commitment policy, which allows for different probabilities of reneging on past promises.