Time to reject the privileging of economic theory over empirical evidence? A Reply to Lawson (2009)

The present financial and economic crisis has revealed a systemic failure of academic economics and emphasized the need to re-think how to model economic phenomena. Lawson (2009) seems concerned that critics of standard models now will fill academic journals with contributions that make the same methodological mistakes, albeit in slightly different guise. In particular, he is rather sceptical to use of mathematical statistical models, such as the CVAR approach, as a way of learning about economic mechanisms. In this paper I discuss whether this is a relevant claim and argue that it is likely to be based on a misunderstanding of what a proper statistical analysis is and can offer. In particular, I argue that the strong evidence of (near) unit roots and (structural) breaks in economic variables suggests that standard economic models need to be modified or changed to incorporate these strong features of the data. Furthermore, I argue that a strong empirical methodology that allows data to speak freely about economic mechanisms, such as the CVAR, would ensure that important information in the data is not over heard when needed. Adequately applied such models would provide us with an early warnings system signalling that the economy is moving seriously out of equilibrium.economic crisis; Dahlem report; CVAR approach; Theory-first; Reality-first; Imperfect Knowledge Expectations; non-stationary data

On the Role of Theory and Evidence in Macroeconomics

This paper, which is prepared for the Inagural Conference of the Institute for New Economic Thinking in King's College, Cambridge, 8-11 April 2010, questions the preeminence of theory over empirics in economics and argues that empirical econometrics needs to be given a more important and inde- pendent role in economic analysis, not only to have some confidence in the soundness of our empirical inferences, but to uncover empirical regularities that can serve as a basis for new economic thinking.

Do prices move together in the long run? An I(2) analysis of six price indices.

The paper discusses methodological questions related to econometric time-series modelling of I(2) data. Long-run and medium-run relationships between two general price indices, the US CPI and WPI and four commodity prices indices, the WBI, CRBI, GSCI, and ECI are investigated in a multivariate sep-up. The statistical concepts of cointegration and polynomial cointegration are related to long-run and short-run price homogeneity.multicointegrated VAR; I(2) analysis; commodity prices

Models and Relations in Economics and Econometrics

Based on a money market analysis the paper discusses possible pitfalls in acroeconomic inference related to inadequate stochastic model formulation. A number of questions related to concepts such as empirical and theoretical steady-states, speed of adjustment, feed-back and interaction effects, and driving forces are addressed within the framework of the cointegrated VAR model. The economic notion of anticipated and unanticipated shocks to a system is discussed from an econometric point of view.I(2); price homogeneity; money market; cointegrated VAR

Wage, Price, and Unemployment Dynamics and the Convergence to Purchasing Power Parity in the Euro Area

The paper discusses the determination of wages, prices, productivity and unemployment in the Euro-wide area in the post Bretton Woods period. The econometric results provide strong evidence on a regime shift at the start of the EMS and the empirical analysis is done separately for the two regimes. Two variables, measuring different aspects of the convergence towards European purchasing power parity, are shown to be crucial for explaining inflation and unemployment behavior in the more recent regime. The results point to the importance of being on a sustainable ppp level when fixing the exchange rates.European unemployment; PPP convergence; Balassa-Samuelsson effect; cointegrated VAR

The Balassa-Samuelson Effect and the Wage, Price and Unemployment Dynamics in Spain

This paper provides an empirical investigation of the wage, price and unemployment dynamics that have taken place in Spain during the last two decades. The aim of this paper is to shed some light on the impact of the European economic integration process on Spanish labour market and the convergence to a European level of prosperity. We find some important lessons to be learnt from the Spanish experience that should be relevant for the new member states. First, high competitiveness in the tradable sector seems crucial for the real and nominal convergence to be successful, implying that the increase of wages in the tradable sector, and subsequently in the nontradable sector, should not be allowed to exceed the growth in productivity. Second, before fixing the real exchange rate it seems crucial that it is on its sustainable (competitive) purchasing power parity level. A real appreciation, as a result of high growth rates during the catching-up period, is likely to be harmful for real growth and employment.Balassa-Samuelson effect; nominal and real convergence; unemployment dynamics; purchasing power parity; cointegrated VAR

Does it matter how aggregates are measured? The case of monetary transmission mechanisms in the euro area

Beyer, Doornik and Hendry (2000, 2001) show analytically that three out of four aggregation methods yield problematic results when exchange rate shifts induce relative-price changes between individual countries and found the least problematic method to be the variable weight method of growth rates. This papers shows, however, that the latter is sensitive to the choice of base year when based on real GDP weights whereas not on nominal GDP weights. A comparison of aggregates calculated with different methods shows that the differences are tiny in absolute value but highly persistent. To investigate the impact on the cointegration properties in empirical modelling, the monetary model in Coenen & Vega (2001) based on fixed weights was re-estimated using flexible real and nominal GDP weights. In general, the results remained reasonably robust to the choice of aggregation method. JEL Classification: C32, C42, E41Aggregation, cointegration, Eurowide money demand, Flexible weights

High Inflation, Hyperinflation and Explosive Roots: The Case of Yugoslavia

The focus is on ’explosive root VAR’ modelling of money, prices, wages, and exchange rates applied to the Jugoslav high inflation/hyperinflation transition period from a centrally planned economy to a more market oriented economy. The I(2) model, which has previously been used to estimate the Cagan model for hyperinflation, is shown to yield incorrect inference when there are explosive roots in the data. The paper develops an econometric framework for the empirical analysis of hyperinflationary episodes and illustrates the importance of exploiting the system dynamics of all the variables in the system for a full understanding of the hyperinflationary mechanisms. The empirical results suggest that excessive nominal wage claims, inflationary expectations and the rate of currency depreciation were the main causes to the Yugoslav hyperinflation rather than the financing of government debt by money printing.Explosive roots; Hyperinflation; Polynomial Cointegration; Transition Economies

An Invariance Property of the Common Trends under Linear Transformations of the Data

It is well known that if X(t) is a nonstationary process and Y(t) is a linear function of X(t), then cointegration of Y(t) implies cointegration of X(t). We want to find an analogous result for common trends if X(t) is generated by a finite order VAR. We first show that Y(t) has an infinite order VAR representation in terms of its prediction errors, which are a linear process in the prediction error for X(t). We then apply this result to show that the limit of the common trends for Y(t) are linear functions of the common trends for X(t). We illustrate the findings with a small analysis of the term structure of interest rates.cointegration vectors; common trends; prediction errors

International Parity Relationships between Germany and the United States: A Joint Modelling Approach

This paper examines the interrelations between the purchasing power parity, uncovered interest parity, the term structure of interest rates and the Fisher real interest rate parity using cointegration analysis. Dynamic adjustment and feed-back effects are estimated jointly in a full system of equations. An important finding is that the very slow, though significant, price adjustment towards sustainable levels of real exchange rates, has been compensated by corresponding changes in the spread of the long-term bond rates. Related to this is the strong empirical support for the weak exogeneity of the long-term bond rates, signifying the importance of the large US trade deficits (i.e. the low levels of US savings) and, hence, their linkage to international finance. Altogether, the results suggest that the transmission mechanisms over the post Bretton Woods period have been significantly different from standard theoretical assumptions.International Parity Conditions