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Book part
Publication date: 21 November 2014

Yixiao Sun

New asymptotic approximations are established for the Wald and t statistics in the presence of unknown but strong autocorrelation. The asymptotic theory extends the usual…

Abstract

New asymptotic approximations are established for the Wald and t statistics in the presence of unknown but strong autocorrelation. The asymptotic theory extends the usual fixed-smoothing asymptotics under weak dependence to allow for near-unit-root and weak-unit-root processes. As the locality parameter that characterizes the neighborhood of the autoregressive root increases from zero to infinity, the new fixed-smoothing asymptotic distribution changes smoothly from the unit-root fixed-smoothing asymptotics to the usual fixed-smoothing asymptotics under weak dependence. Simulations show that the new approximation is more accurate than the usual fixed-smoothing approximation.

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Book part
Publication date: 21 November 2014

Abstract

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Essays in Honor of Peter C. B. Phillips
Type: Book
ISBN: 978-1-78441-183-1

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Article
Publication date: 7 August 2007

Pär Sjölander

In what seems as an infinitely ongoing debate regarding the purchasing power parity (PPP) theory, this paper seeks to question the strength of the scientific “evidence”…

Abstract

Purpose

In what seems as an infinitely ongoing debate regarding the purchasing power parity (PPP) theory, this paper seeks to question the strength of the scientific “evidence” put forward by the PPP revisionists

Design/methodology/approach

In this paper, the validity of the PPP revisionists' scientific evidence supporting long‐run PPP is questioned based on the replication of an influential review study that is considered by PPP revisionists to exhibit “some of the strongest evidence” in favour of the PPP theory.

Findings

By simulation experiments it is demonstrated that the traditional PPP unit root tests are non‐robust to the empirically identified (G)ARCH distortions. Due to (G)ARCH distortions, over‐rejections for the traditional unit root tests are shown to be a problem that potentially misleads researchers to believe that long‐run PPP holds under circumstances when it is in fact not valid. As a potential remedy to this problem, a new unit root test is introduced which is robust to conditional heteroscedasticity disturbances, and in contrast to traditional unit root tests, it exhibits no significant empirical support for the PPP theory.

Originality/value

The study illustrates that the PPP revisionists' unit root tests cannot reliably test the PPP hypothesis in the presence of (G)ARCH distortions, due to bad power and size properties. Perhaps it is time to conclude that, based on the currently existing research, it is virtually impossible to empirically come to a credible conclusion regarding whether long‐run PPP holds or not.

Details

Journal of Economic Studies, vol. 34 no. 3
Type: Research Article
ISSN: 0144-3585

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Article
Publication date: 17 May 2013

Priyanka Jain, Vishal Vyas and Ankur Roy

This paper aims to study the weak form of efficiency of Indian capital market during the period of global financial crisis in the form of random walk.

Abstract

Purpose

This paper aims to study the weak form of efficiency of Indian capital market during the period of global financial crisis in the form of random walk.

Design/methodology/approach

The study considered daily closing prices of S&P CNX Nifty, BSE, CNX100, S&P CNX 500 from April 1, 2005 to March 31, 2010. The data source is the equity market segment of NSE and BSE. Both parametric and nonparametric tests (“ex‐posts” in nature) are applied for the purpose of testing weak‐form efficiency. The parametric tests include Augmented Dickey‐Fuller (ADF) unit root tests and nonparametric tests include Phillips‐Perron (PP) unit root tests and Run test. ADF tests use a parametric autoregressive structure to capture serial correlation and PP tests use non‐parametric corrections based on estimates of the long‐run variance of ΔYt.

Findings

The results suggested that the Indian stock market was efficient in its weak form during the period of recession. It means that investors should not be able to consistently earn abnormal gains by analysing the historical prices. Hence one should not be able to make a profit from using something that everybody else knows.

Practical implications

The study reports that all the stocks in these selected indices are fundamentally strong and their prices are not influenced largely by historical prices and other relevant factors which came from industry and any other information that is publically available. Thus it can be concluded that the Indian stock market was informationally efficient and no investor can usurp any privileged information to make abnormal profits.

Originality/value

Where past studies have examined the weak‐form of efficiency of various markets and the effect of globalisation and global financial crisis on the various sectors of developing and emerging economies, this paper attempts to study the weak form of efficiency of the Indian capital market in the period of recession in the form of random walk.

Details

Journal of Advances in Management Research, vol. 10 no. 1
Type: Research Article
ISSN: 0972-7981

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Article
Publication date: 13 April 2018

Emmanuel Joel Aikins Abakah, Paul Alagidede, Lord Mensah and Kwaku Ohene-Asare

The purpose of this paper is to re-examine the weak form efficiency of five African stock markets (South Africa, Nigeria, Egypt, Ghana and Mauritius) using various tests…

Abstract

Purpose

The purpose of this paper is to re-examine the weak form efficiency of five African stock markets (South Africa, Nigeria, Egypt, Ghana and Mauritius) using various tests to assess the impact of non-linearity effect and thin trading which are prevalent in African markets on market efficiency.

Design/methodology/approach

The weekly returns of S&P/IFC return indices for five African countries over the period 2000-2013 were obtained from DataStream and analyzed. The study adopted the newly developed Non-Linear Fourier unit root test advanced by Enders and Lee (2004, 2009) which allows for an unknown number of structural breaks with unknown functional forms and non-linearity in data generating process of stock prices series to test the Random Walk Hypothesis (RWH) for the five markets, and an augment regression model.

Findings

In light of the empirical evidence the author(s) using Non-linear Fourier Unit Root Test only fail to reject the RWH for South Africa, Nigeria and Egypt leading to the conclusion that these markets follow the RWH and weak-form efficient whilst Ghana and Mauritius are weak-form inefficient. Besides, evaluating non-linear models without adjusting for thin trading effect shows that, South Africa and Ghana markets are weak-form efficient while Nigeria, Egypt and Mauritius are not. However, after accounting for thin trading effect, the author(s) find that South Africa and Egypt markets follow the RWH. The findings imply that market efficiency results depend on the methodology used.

Originality/value

This paper provides further evidence on stock market efficiency in emerging markets. The finding suggests that thin trading and non-linearity effect influences markets efficiency tests in African stock markets. Thus, recent structural adjustment and liberalization policies have not enhanced stock market operations in Africa. This paper therefore has implications for policy makers and international investors.

Details

International Journal of Managerial Finance, vol. 14 no. 3
Type: Research Article
ISSN: 1743-9132

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Article
Publication date: 25 January 2008

Batool Asiri

This study seeks to measure the behaviour of stock prices in the Bahrain Stock Exchange (BSE), which is expected to follow a random walk. The aim of the study is to…

Abstract

Purpose

This study seeks to measure the behaviour of stock prices in the Bahrain Stock Exchange (BSE), which is expected to follow a random walk. The aim of the study is to measure the weak‐form efficiency.

Design/methodology/approach

Random walk models such as unit root and Dickey‐Fuller tests are used as basic stochastic tests for a non‐stationarity of the daily prices for all the listed companies in the BSE. In addition, autoregressive integrated moving average (ARIMA) and exponential smoothing methods are also used. Cross‐sectional‐time‐series is used for the 40 listed companies over the period 1 June 1990 up until 31 December 2000.

Findings

Random walk with no drift and trend is confirmed for all daily stock prices and each individual sector. Other tests, such as ARIMA (AR1), autocorrelation tests and exponential smoothing tests also supported the efficiency of the BSE in the weak‐form.

Practical implications

The finding of the study is a necessary piece of information for all investors whether in Bahrain or dealing with Bahrain stock market. Listed firms could also benefit from the findings by seeing the true picture of their stock price. Since, Bahrain is considered as an emerging market, the new methodologies used could be replicated for all other emerging markets. In addition, the finding is used as a base for testing the market efficiency in the semi‐strong form, which has not yet been tested by any researcher.

Originality/value

This study will add value to the literature of market efficiency in emerging market since it is the only study which covers all the listed companies and over a long period of time. To confirm the weak‐form efficiency in Bahrain, the study is unique in using five different methods in the same paper which have not been found in the previous literature.

Details

International Journal of Emerging Markets, vol. 3 no. 1
Type: Research Article
ISSN: 1746-8809

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Article
Publication date: 1 January 1993

Bruno Amable, Jérôme Henry, Frédéric Lordon and Richard Topol

Hysteresis is one of the main concepts used in Layard, Nickell andJackman′s book, Unemployment: Macroeconomic Performance and theLabour Market. Attempts to clarify the…

Abstract

Hysteresis is one of the main concepts used in Layard, Nickell and Jackman′s book, Unemployment: Macroeconomic Performance and the Labour Market. Attempts to clarify the concept of hysteresis, from its formal representation to its empirical applications. Emphasizes the idea that hysteresis refers back to a given set of formal properties, independently of the phenomenologies within which it is liable to be encountered. In economics, the fields concerned may indeed vary a lot (labour market, foreign trade, etc.). By highlighting all the formal properties of hysteresis, shows how the assimilation of phenomena characterized by a zero eigenvalue for linear systems (or unitroot systems for discrete‐time processes) is wrong and, moreover, how the imprecise use of the concepts can lead to the particular constraints affecting unitroot econometrics being overlooked.

Details

Journal of Economic Studies, vol. 20 no. 1/2
Type: Research Article
ISSN: 0144-3585

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Abstract

Details

Economic Complexity
Type: Book
ISBN: 978-0-44451-433-2

Abstract

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The Impacts of Monetary Policy in the 21st Century: Perspectives from Emerging Economies
Type: Book
ISBN: 978-1-78973-319-8

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Article
Publication date: 12 March 2019

Cosimo Magazzino

This study aims to investigate the stationarity and convergence of CO2 emissions series in MENA countries. The stationarity and unit root properties of per capita carbon…

Abstract

Purpose

This study aims to investigate the stationarity and convergence of CO2 emissions series in MENA countries. The stationarity and unit root properties of per capita carbon dioxide (CO2) emissions series are explored by an increasing amount of studies, which use different methodologies. Examining the time series properties of energy and environmental series is crucial for both researchers and the policymakers, given the close link between energy, environment and the real economy. In fact, if energy exhibits the presence of a unit root, this suggests that this series does not revert to its equilibrium level after being hit by a shock.

Design/methodology/approach

The contribution of this work is twofold. First, to the author’s knowledge, a very little attention has been paid to the topics of stationarity and convergence of CO2 emissions in the case of Middle East and North Africa (MENA) member states, especially in a panel context. Convergence analyses of CO2 emissions for MENA countries can improve the knowledge of energy and environmental scenario of the area, giving some ideas for appropriate future policies. Second, this is the first study that jointly analyzed time series and panel data properties of emissions series for these countries.

Findings

The author finds that relative per capita CO2 emissions in the 19 MENA countries are a mixture of I(0) and I(1) processes and there is a weak evidence to support the stationarity of CO2 emissions. After having verified the presence of cross-sectional dependence in the series, the panel unit root tests in presence of cross-section dependence show strong evidence in favor of non-stationarity. In addition, after performing tests for ß-convergence, it is also found that per capita CO2 emissions are converging on average in 11 out of 19 sample’s countries, while s-convergence analysis reveals that the variance of per capita CO2 emissions decreased over time, which is an indication of convergence.

Originality/value

Important policy implications emerge from the empirical results. Sustainable environmental and energy policies rely heavily on the CO2 series’ properties. In this regard, determining whether shocks to CO2 emissions are permanent or transitory is important for setting feasible goals for sustainable environmental policies. Given that per capita CO2 emissions are essentially associated with a quality of life, the issues of their reduction have been the leading agenda in energy and environmental management over the past two decades.

Details

International Journal of Energy Sector Management, vol. 13 no. 4
Type: Research Article
ISSN: 1750-6220

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