## Competing theories of the wage-price spiral and their forecast ability

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2017

##### Authors

Mokoka, Tshepo

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This thesis contains three main chapters. The rst chapter employs wageprice spirals to generate ination forecasts for Australia, Canada, France, South Korea, South Africa, United Kingdom and the United States. We use three competing specications of the wage-price spirals, and test which specication provides the best forecasts of price ination. For each specication we provide one quarter, four quarter and eight quarter ahead dynamic forecasts of price ination. The rst two wage-price spirals in the rst chapter are from the Keynesian tradition from te standpoint of expectations formation. The chapter also considers the New Keynesian wage-price spiral. We use the Root Means Square Error and the Clark and West statistic to compare the performance of ination forecasts from the three competing wage-price spirals that we consider in the rst chapter of the thesis. We nd that the New Keynesian wage and price specication su⁄ers from the wrong sign problem, and its forecasts of price ination generally outperform those from the old Keynesian wage price spiral for the eight quarter ahead time horizon. The usefulness of this nding to the conduct of monetary policy is limited due to the wrong sign problem of the forcing variable in the New Keynesian wageprice spiral. We also nd that the Flaschel type specication of price and wage ination produce four and eight quarter head ination forecasts that are better than those from the Fair type specication. We further nd that the Fair type specication price and wage equation produce the best forecasts of ination for the one quarter ahead time horizon.
In the second chapter, we estimate natural variables and test their ability to explain the ination process for the eight countries that we consider. We use the traditional Keynesian wage-price spiral and the triangle system approaches to estimate the NAIRU and potential output. In the case of the traditional Keynesian wage-price spiral, the price Phillips curve, which can be specied as a triangle Phillips curve, features backward looking ination expectations and nominal wage ination, the output gap and supply shocks. The nominal wage Phillips curve features ination expectations and price ination and the unemployment gap. The presence of price ination in the nominal wage Phillips curve and the presence of nominal wage ination in the price Phillips curve leads to the interaction between the two Phillips curves. The separate demand pressure terms allows for their identication since, as
someauthorsintheliteraturearguethatthegoodsandlabourmarketsdonot move in line with each other. To compute the NAIRU and potential output using the Keynesian approach, we rstly exploit the information contained in vector of unobservable by estimating the wage-price spiral in di⁄erence form using the Seemingly Unrelated Regression method. We use this regression method in order to control for any correlation that may exist between errors in the price and wage Phillips curves. This allows us to solve for the vector of potential output and the NAIRU. We then the moving average technique in order to avoid problems associated with the HP lter for smoothing. Due to data availability, use the MA (20) approximation of the low pass lter after padding the endpoints with forecasts from an AR(4) process. We follow a similar procedure in the estimation of the estimation of the NAIRU and potential output for the triangle system approach. To test which method produces the best natural variables, we t the gaps that are computed from the NAIRU and potential output in a simple single equation price Phillips curve. To test which specication produces the best natural varibles we use a simple single equation triangle price Phillips curve. We nd that the output gaps computed from the two competing approaches are signicantly correlated, the same applies to the unemployment gaps computed from the two approaches. We nd that the quality of unemployment rate gaps computed from the Keynesian and triangle system approach to produce similar quality of results when tted to a single equation triangle price Phillips curve. The Keynesian approach slightly outperforms the triangle systems approach in the when considering the output gap as a proxy for the demand pressure. These results indicate that the wage-price spiral still remains an important tool in the determination of the dynamics ination.
In the third chapter, we analyze the relationship between monetary policy and natural variables for Australia, Canada, France, South Korea, South Africa, United Kingdom and the United States. We do this by specifying a relationship between natural rates and the real interest rate. The theoretical relationship between the two variables is positive in the case of the NAIRU and negative through Okuns law in the case of potential output. We regress the natural variable against a constant and the MA(8) of the real interest rate. We nd that the parameter of the real interest rate generally has a correct sign when considering the Keynesian approach computed NAIRUs, with only four being signicant. In the case of the triangle system approach NAIRU, we nd that the real interest rate parameter has a correct sign and signicant four countries. We nd that NAIRUs computed using di⁄erent methodologies can produce a di⁄erent reference point for policy makers. We then introduce hysteresis in the relationship between monetary policy and the NAIRU. We then nd that the interest rate parameter generally has a incorrect sign across the three approaches. The HP ltering approach which we include in our study for comparison purposes produces incorrect correlation for all the countries, while the Keynesian approach negative correlation for seven countries, and the triangle system approach in six countries. In the case of the relationship between monetary policy and potential output, we nd that the real interest rate parameter has an incorrect sign. When introducing hysteresis in the relationship between monetary policy and potential we nd that, unlike in the case of the NAIRU this plays signicant role in the relationship.

##### Description

A thesis submitted to the Faculty of Commerce, Law and Management, University of the Witwatersrand, Johannesburg, in fullment of the requirements for the Doctor of Philosophy in Economics Degree, June 2017

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##### Citation

Mokoka, Tshepo (2017) Competing theories of the wage-price spiral and their forecast ability, University of the Witwatersrand, Johannesburg, <https://hdl.handle.net/10539/24147>