Zeynel Abidin Ozdemir

Efficient market hypothesis: evidence from a small open-economy

This article studies the efficient market hypothesis for the Istanbul Stock Exchange National 100 (ISEN 100) price index within the Lumsdaine and Papell two structural breaks unit root test framework. The main finding of the article shows that the ISEN 100 index is characterized by a unit root with two structural breaks, which is consistent with the efficient market hypothesis. In addition, the article applies the augmented Dickey–Fuller test, runs test and the variance-ratio test to test the weak-form efficiency of the ISEN 100. The analyses are repeated for three sub-periods delineated in view of the endogenously determined break points.

Asymmetric and Time‐Varying Causality between Inflation and Inflation Uncertainty in G‐7 Countries

We use Granger causality tests within a conditional Gaussian Markov switching vector autoregressive (MS‐VAR) model using monthly data for G‐7 countries covering the period 1959:12–2008:10 to examine the relationship between inflation and inflation‐uncertainty. The MS‐VAR model allows us to model parameter time‐variation so as to reflect changes in Granger causality, assuming that these changes are stochastic and governed by an unobservable Markov chain. Inflation uncertainty is measured as the conditional variance generated by a Fractionally Integrated Smooth Transition Autoregressive Moving Average‐Asymmetric Power ARCH (FISTARMA‐APARCH) model. The distinguishing feature of our approach from the previous studies is the determination of the sign of the Granger causality relationship between inflation and its uncertainty over time. First, using a rolling VAR model, we show that the relationship between inflation and inflation uncertainty is time varying with frequent breaks. Second, using the MS‐VAR model, we obtain strong evidence in favour of the Hollands ‘stabilizing Fed hypothesis’ for Canada, France, Germany, Japan, United Kingdom, and the United States. We also find evidence in favour of the Friedman hypothesis for Canada and the United States.

Fiscal Policy Shocks and the Dynamics of Asset Prices: The South African Experience

This study assesses how fiscal policy affects the dynamics of asset markets, using Bayesian vector autoregressive models. We use sign restrictions to identify government revenue and government spending shocks, while controlling for generic business cycle and monetary policy shocks. In addition to examining the effects of anticipated and unanticipated revenue and spending shocks, we also analyse three types of fiscal policy scenarios: a deficit-financed spending increase, a balanced budget spending increase (financed with higher taxes), and a deficit-financed tax cut (revenue decreases but government spending stays unchanged). Using South African quarterly data from 1966:Q1 to 2011:Q2, we show that a deficit spending shock does not affect house prices, but temporarily exerts a positive effect on stock prices. With a deficit-financed tax cut shock, house prices increase persistently while stock prices increase quickly, but only temporarily. A balanced budget shock permanently decreases house prices and temporarily reduces stock prices.

Dynamics of Inflation, Output Growth and Their Uncertainty in the UK: An Empirical Analysis

The aim of this paper is to analyse the dynamics relationships between inflation, output growth, and real and nominal uncertainty using the VARFIMA-BEKK MGARCH model of inflation and output growth and quarterly data for the UK covering the 1957:Q2–2006:Q4 period. The analysis is also done for the three sub-periods determined by considering the structural changes such as the Great Moderation in the series of the UK. Two findings are obtained. First, the evidence obtained from the full period supports a number of important conclusions, one of which is mixed evidence regarding the effect of inflation on inflation uncertainty, another one being strong evidence regarding the positive effect of inflation uncertainty on inflation and output growth. Taking this into account, it is possible to put forward that an essential determinant of economic growth is uncertainty about the inflation rate. The last finding for this period is that output growth uncertainty is a positive determinant of the inflation and output growth rate. Second, the evidence found from the sub-periods is that there are no linkages between inflation, output growth and their volatility.

The purchasing power parity hypothesis in Turkey: evidence from nonlinear STAR error correction models

This study re-examines the validity of long-run purchasing power parity (PPP) hypothesis for Turkey using nonlinear cointegration technique. The finding of this article provides the evidence that the long run PPP hypothesis is valid by using nonlinear cointegration technique. This finding argues the validity of the long-run PPP hypothesis in bilateral Turkish real exchange rates with the USA, which is also supported by Sarno (2000) and Erlat (2004).

LPPLS bubble indicators over two centuries of the S&P 500 index

The aim of this paper is to present novel tests for the early causal diagnostic of positive and negative bubbles in the S&P 500 index and the detection of End-of-Bubble signals with their corresponding confidence levels. We use monthly S&P 500 data covering the period from August 1791 to August 2014. This study is the first work in the literature showing the possibility to develop reliable ex-ante diagnostics of the frequent regime shifts over two centuries of data. We show that the DS LPPLS (log-periodic power law singularity) approach successfully diagnoses positive and negative bubbles, constructs efficient End-of-Bubble signals for all of the well-documented bubbles, and obtains for the first time new statistical evidence of bubbles for some other events. We also compare the DS LPPLS method to the exponential curve fitting and the generalized sup ADF test approaches and find that DS LPPLS system is more accurate in identifying well-known bubble events, with significantly smaller numbers of false negatives and false positives.

International Labour Force Participation Rates by Gender: Unit Root or Structural Breaks?

This paper examines the possibility of unit roots in the presence of endogenously determined multiple structural breaks in the total, female and male labour force participation rates (LFPR) for Australia, Canada and the USA. We extend the procedure of Gil-Alana (2008) for single structural break to the case of multiple structural breaks at endogenously determined dates using the principles suggested by Bai and Perron (1998). We use the Robinson (1994) LM test to determine the fractional order of integration. We find that endogenously determined structural breaks render the total, female and male LFPR series stationary or at best mean-reverting.

Unemployment and labour force participation in Turkey

ABSTRACT This article investigates the relationship between labour force participation rate and unemployment rate in Turkey a developing country. Cointegration analysis is carried out for the aggregate and gender-specific series. The findings indicate that there is no long-run relationship between labour force participation and unemployment rates in Turkey. Thus, unlike in the case of the developed countries, the unemployment invariance hypothesis is supported in Turkey.

On the Nonlinear Causality between Inflation and Inflation Uncertainty in the G3 Countries

This study examines the dynamic relationship between monthly inflation and inflation uncertainty in Japan, the US and the UK by employing linear and nonlinear Granger causality tests for the 1957: 01–2006: 10 period. Using a generalised autoregressive conditional heteroskedasticity (GARCH) model to generate a measure of inflation uncertainty, the empirical evidence from the linear and nonlinear Granger causality tests indicate a bidirectional causality between the series. The estimates from both the linear vector autoregressive (VAR) and nonparametric regression models show that higher inflation rates lead to greater inflation uncertainty for all countries as predicted by Friedman (1977). Although VAR estimates imply no significant impact, except for Japan, nonparametric estimates show that inflation uncertainty raises average inflation in all countries, as suggested by Cukierman and Meltzer (1986). Thus, inflation and inflation uncertainty have a positive predictive content for each other, supporting the Friedman and Cukierman-Meltzer hypotheses, respectively.

Fiscal Policy Shocks and the Dynamics of Asset Prices

This study assesses how fiscal policy affects the dynamics of asset markets, using Bayesian vector autoregressive models. We use sign restrictions to identify government revenue and government spending shocks, while controlling for generic business cycle and monetary policy shocks. Using South African quarterly data from 1966: Q1 to 2011: Q2, we find that fiscal spending shocks affect stock prices more than house prices. Both spending and revenue shocks affect stock prices whereas only revenue shocks affect house prices.