Monetary policy rules and directions of causality: A test for the euro area

Abstract

Using a VAR model in first differences with quarterly data for the euro zone, the study aims to ascertain whether decisions on monetary policy can be interpreted in terms of a “monetary policy rule” with specific reference to the so-called nominal GDP targeting rule (Hall and Mankiw, 1994 Granger, C.W.J. “Investigating Causal Relations by Econometric Models and Cross-Spectral Methods.” Econometrica, 1969, 37 (3), 424–438.[Crossref], [Web of Science ®] , [Google Scholar]; McCallum, 1988 McCallum, B. “Nominal GDP Targeting”, Shadow Open Market Committee, October 21, 2011. [Google Scholar]; Woodford, 2012 Taylor, J.B., Williams, J.C. “Simple and Robust Rules for Monetary Policy”, NBER Working Paper No. 15908, April, 2010. [Google Scholar]). The results obtained indicate a causal relation proceeding from deviation between the growth rates of nominal gross domestic product (GDP) and target GDP to variation in the three-month market interest rate. The same analyses do not, however, appear to confirm the existence of a significant inverse causal relation from variation in the market interest rate to deviation between the nominal and target GDP growth rates. Similar results were obtained on replacing the market interest rate with the European Central Bank refinancing interest rate. This confirmation of only one of the two directions of causality does not support an interpretation of monetary policy based on the nominal GDP targeting rule and gives rise to doubt in more general terms as to the applicability of the Taylor rule and all the conventional rules of monetary policy to the case in question. The results appear instead to be more in line with other possible approaches, such as those based on post Keynesian analyses of monetary theory and policy and more specifically the so-called solvency rule (Brancaccio and Fontana, 2013 ———. Macroeconomics, 2nd ed., Pearson Education Company, ch. 30. [Google Scholar], 2015 Brancaccio, E. The Central Banker as “Regulator” of Conflict. In G. Fontana and M. Setterfield (eds.), Macroeconomic Theory and Macroeconomic Pedagogy. Basingstoke: Palgrave Macmillan, 2009, 295–308.[Crossref] , [Google Scholar]). These lines of research challenge the simplistic argument that the scope of monetary policy consists in the stabilization of inflation, real GDP, or nominal income around a “natural equilibrium” level. Rather, they suggest that central banks actually follow a more complex purpose, which is the political regulation of the financial system with particular reference to the relations between creditors and debtors and the related solvency of economic units.