Variance ratio tests of the random walk hypothesis for European emerging stock markets

The hypothesis that stock market price indices follow a random walk is tested for five European emerging markets, Greece, Hungary, Poland, Portugal and Turkey, using the multiple variance ratio test. In four of the markets, the random walk hypothesis is rejected because of autocorrelation in returns. For the Istanbul market, which had markedly higher turnover than the other markets in the 1990s, the stock price index follows a random walk. This contrasts with the results of earlier research, carried out for periods of lower turnover, which rejected the random walk hypothesis.     

Cointegration and causality between macroeconomic variables and stock market returns

The purpose of this study is to investigate whether current economic activities in Korea can explain stock market returns by using a cointegration test and a Granger causality test from a vector error correction model. This study finds that the Korean stock market reflects macroeconomic variables on stock price indices. The cointegration test and the vector error correction model illustrate that stock price indices are cointegrated with a set of macroeconomic variables—that is, the production index, exchange rate, trade balance, and money supply—which provides a direct long-run equilibrium relation with each stock price index. However, the stock price indices are not a leading indicator for economic variables, which is inconsistent with the previous findings that the stock market rationally signals changes in real activities.     

Measuring informational efficiency of the European carbon market — A quantitative evaluation of higher order dependence

This paper introduces a new method for measuring nonlinear predictability in financial price changes: the so-called intermittency coefficient, a parameter of the multifractal random walk model by Bacry et al. (2001). As the intermittency coefficient can quantify the degree of nonlinear deviation from a random walk, we employ its estimates from financial data as a proxy for the loss of financial market efficiency. In addition, we propose a new statistical test of the random walk hypothesis. In an empirical application using data from the largest currently existing market for tradable pollution permits, the European Union Emissions Trading Scheme (EU ETS), we show that the degree of efficiency of this market remains largely unchanged over the period of observation 2008–2019. This suggests that the market has reached a mature state: informational efficiency in Phase III remains at a level comparable to Phase II. What is more, the EU ETS is found to be more efficient than the US stock market. This result, surprising as such, is largely attributable to the lower exposure to global economic shocks of the EU ETS.     

STOCK PRICES AND EXCESSIVE VOLATILITY: SOME EVIDENCE FOR THE FT ORDINARY SHARE INDEX

In this paper the efficiency of the UK stock market is examined using the FT Ordinary share price and dividend indices for the period January 1947 to June 1987. In particular, we examine the validity of the present value model of stock prices using a vector error correction model (VECM). Amongst the findings reported in the paper are that stock prices and dividends are cointegrated and the cross-equation restrictions imposed on the VECM are strongly rejected.     

Mean reversion versus random walk in G7 stock prices evidence from multiple trend break unit root tests

This paper provides evidence on the random walk hypothesis in G7 stock price indices using unit root tests which allow for one and two structural breaks in the trend. Of the seven countries we find, at best, evidence of mean reversion in the stock price index of Japan. Thus, overall, our results support the random walk hypothesis. We also consider the implications of the identified structural breaks for movement in stock prices over time. Our main conclusion from this exercise is that the second break in stock prices has had a detrimental effect on movements in stock prices in the G7 countries.     

Bubbles in the dividend–price ratio? Evidence from an asymmetric exponential smooth-transition model

Recent stock price movements have led to a re-examination of the present value model. An increasing belief is that although dividends and prices are indeed cointegrated, they may exhibit non-linear dynamics in the process of reversion. This paper implements an empirical model designed to capture two possible explanations for such non-linearity, namely transaction costs and noise traders. Utilising data from a number of countries we show that the dynamics of the log dividend yield are, first, characterised by an inner random walk regime, where the benefits of engaging in trade do not outweigh the costs and so the process moves randomly. Second, a reverting outer regime where the dynamics of reversion differ between positive and negative deviations, such that price rises greater than the level supported by dividends exhibit a greater degree of persistence than price falls relative to dividends.     

An information-based model of target stock price runup in the market for corporate control

The stock price runup of target firms in the market for corporate control has been anecdotally attributed to inside trading. Moreover, the empirical merger and acquisitions literature documents a time-varying level and duration of the stock price runup of target firms. Using a market microstructure approach, we model stock price runup as a stochastic process that shifts between a random walk without drift and a predictable process dependent on a parsimonious set of state variables. Consistent with the market microstructure literature, predictability in prices can be exploited only by the informed trader. The model is capable of explaining the complex stylized facts observed in stock price runup. It is also consistent with the merger wave literature, as we find that capital liquidity, economic growth, and market valuations drive the complex dynamics of stock price runup.     

Using Daily High/Low Time to Test for Intraday Random Walk in Two Index Futures Markets

This paper investigates the time of the daily high/low price in the Hang Seng and S&P 500 index futures and uses it to test for deviation from the predictive behavior of an intraday random walk model. Theoretical distributions of the daily high/low time under the random walk model are derived assuming either uniform or time-varying intraday trading speed. We show that under a random walk model, daily high/low time is more likely to occur near market open/close than in the middle of the trading day. Empirical distributions of the daily high/low time are compared with its theoretical distributions to test for the random walk model. It is found that for the intraday movement of the S&P 500 futures, the random walk hypothesis cannot be rejected. However, it is discovered that in the Hong Kong market, daily high/low time tends to appear significantly more often than is predicted by the random walk model in the first 15-minute time interval when the market opens in the morning or in the afternoon. The results remain valid even after we have taken the time-varying trading speed into account. By comparing the price behavior across markets, we can better understand the microstructure of the futures market.     

The Random Walk Hypothesis in the Spanish Stock Market: 1980–1992

In this paper we test the random walk hypothesis in the Spanish stock market using disaggregated daily data base spanning the period January 1980 to December 1992. We find that daily returns are strongly correlated and nonlinear dependent. Furthermore, using the variance-ratio test, that is robust to heteroscedasticity, the results suggest that the rejection of the random walk hypothesis cannot be attributed completely to the effects of time varying volatilities. In this sense, the price changes can be potentially predictable over, at least, short time spans.     

Economic interdependence and common stochastic trends: A comparative analysis between EMU and non-EMU stock markets

Whether economic interdependence among countries is a contributing factor to cointegration and common stochastic trends in international stock markets is indiscernible due to contradictory results from prior empirical work. This study aims to add clarity to this issue through a more distinct grouping of countries and methodological enhancements. A comparative analysis of cointegration is conducted between stock market price indices of major Economic and Monetary Union (EMU) and non-EMU countries. The conventional Johansen methodology is augmented with several diagnostic techniques (that have not been all inclusive in previous studies) to ensure the robustness of test results. Major findings pertinent to investors and policymakers are that economic interdependence appears to be the important contributing factor and that the U.S. stock market does not exert influences on long-run performances of other included stock markets. Furthermore, while the UK is not an EMU member, it may be viewed as a quasi EMU participant due to its stock market being cointegrated with and yet one of the common stochastic trends (besides those of Germany, Italy, and the Netherlands) within the EMU stock markets under investigation.     

Fluctuations and response in financial markets: the subtle nature of ‘random’ price changes

Using trades and quotes data from the Paris stock market, we show that the random walk nature of traded prices results from a very delilcated interplay between two opposite tendencies: long-range correlated market orders that lead to super-diffusion (or persistence), and mean revrting limit orders that lead to sub-diffusion (or anti-persistence). We define and study a model where the price, at any instant, is the result of the impact of all past trades, mediated by a non-constant ‘propagator’ in time that describes the response of the market to a single trade. Within this model, the market is shown to be, in a precise sense, at a critical point, where the price is purely diffusive and the average response function almost constant. We find empirically, and discuss theoretically, a fluctuation-response relation. We also discuss the fraction of truly informed market orders, that correctly anticipate short-term moves, and find that it is quite small.     

Asymmetric dynamic relations between stock prices and mutual fund units in Japan. An application of hidden cointegration technique

This paper examines “causality” effects between mutual fund flows and stock index prices in Japan. In particular, both the short and long run dynamics between stock prices and fund units are investigated. The novelty of our paper is the use of the hidden cointegration technique which attempts to capture heterogeneous fund flow reactions when stock index prices move up or down. Moreover, we employ the crouching error correction model (CECM) to assess the relationship between stock market movements and fund flow changes. The results show that stock prices and mutual fund units are cointegrated. In the case of positive movements there is a bi-directional effect interconnecting them, whereas for negative movements, causality runs only from fund flows to stock prices. The dynamics structure provides evidence that market microstructure, taxation and investors' sentiment affect stock price and unit formation.     

Price Linkages Between the US,Japan and UK Stock Markets

This study presents an empirical analysis of the short- and long-term relationships among stock prices in the US, Japan and the UK. We re-examine the evidence of market linkages and cointegration between S&P 500, Nikkei 225 and FTSE-100 stock indices. The results suggest that mature markets are cointegrated, indicating a stationary long-run relationship. Furthermore, Granger causality tests show a bi-directional causality between Nikkei 225–FTSE-100, and unidirectional causalities between S&P 500–FTSE-100 and S&P 500–Nikkei 225. These findings suggest that the potential for diversifying risk by investing in mature markets is limited.     

An Analysis of the Interrelationships Among the Major World Stock Exchanges

The method of principal component is used in this paper to analyse the interrelationship among the world's major stock exchanges. The major finding is that the interrelationship is unstable over time. This finding proves that any ex ante prediction of price indices is impossible, and it suggests that the indices of world equity markets can move in a random walk fashion. The consequences to international portfolio diversification should be obvious.     

The statistical evolution of prices on the Istanbul stock exchange

This study documents the statistical properties of the stock returns on the Istanbul Stock Exchange (ISE) for the January 1988 to December 1999 period and tries to assess the evolution of the underlying stochastic structure over this time period. It also investigates empirically the relative efficiency of the ISE to test whether the rapid development of this market over the last decade caused it to become a relatively more efficient market. This is accomplished through a number of parametric and non-parametric tests of the random walk hypothesis using daily, weekly and monthly observations of the value-weighted ISE-100 index series. The emphasis is more on the evolution of the price process than on static tests of a random walk model as such. The findings indicate that the price mechanism in the ISE has evolved into a more informationally efficient process in little more than a decade of existence.     

Tests of Analysts' Overreaction/Underreaction to Earnings Information as an Explanation for Anomalous Stock Price Behavior

This study examines whether security analysts underreact or overreact to prior earnings information, and whether any such behavior could explain previously documented anomalous stock price movements. We present evidence that analysts' forecasts underreact to recent earnings. This feature of the forecasts is consistent with certain properties of the naive seasonal random walk forecast that Bernard and Thomas (1990) hypothesize underlie the well-known anomalous post-earnings-announcement drift. However, the underreactions in analysts' forecasts are at most only about half as large as necessary to explain the magnitude of the drift. We also document that the “extreme” analysts' forecasts studied by DeBondt and Thaler (1990) cannot be viewed as overreactions to earnings, and are not clearly linked to the stock price overreactions discussed in DeBondt and Thaler ( 1985 , 1987 ) and Chopra, Lakonishok, and Ritter (Forthcoming). We conclude that security analysts' behavior is at best only a partial explanation for stock price underreaction to earnings, and may be unrelated to stock price overreactions.     

THE ROLE OF ACCOUNTING INFORMATION IN STOCK MARKET LIBERALIZATION: EVIDENCE FROM KOREA

Stock market liberalization is a decision by a country’s government to allow foreigners to buy securities in that country’s capital market. This study examines how the liberalization of the Korean stock market affected stock price behavior and changed the role of accounting information for investment decisions. The Korean stock market opened its door to foreign investment in 1991. Prior to this, market inefficiencies, such as the superfluous co-movement of stock prices with industry or market indices or investment based on rumor and speculation, were widespread. Since the opening of the stock market to foreigners, a more rational pricing behavior has emerged. This setting provides a unique opportunity to investigate how stock price behavior has changed with market liberalization and what was the role of accounting information in this process. Our results indicate that the co-movement behavior of stock prices by industry decreased and stock price differentiation based on individual firm characteristics increased after market liberalization. The results also show that the explanatory power of accounting numbers increased after market liberalization. Overall, the results imply that foreign investors contributed to the improvement of market efficiency with the opening up of capital markets in Korea. We believe that our results provide useful evidence to other capital markets that are in a similar situation.     

Price distortion induced by a flawed stock market index

Despite the introduction of sophisticated stock market indices, investors often trade portfolios of the flawed indices to change their exposure to the market. In this study, we show that these transactions cause significant mispricing in individual stocks, especially during periods of significant market movement. As an influential, albeit flawed, stock index, we focus on the Nikkei 225. We find index constituents that are excessively weighted on the index, experience buying (selling) pressure when the stock market surges (falls), and experience price corrections after such periods of change. In contrast, non-constituent stocks do not experience such trading pressure.     

Dynamic Linkages Between the Greater China Economic Area Stock Markets—Mainland China,Hong Kong,and Taiwan

This research examines the linkages among three Greater China Economic Area (GCEA) stock markets, including Mainland China, Hong Kong, and Taiwan, and two developed markets, Japan and the United States. We find that: (1) a random walk model is outpredicted by an autoregressive GARCH model and an ARIMA model in all three GCEA markets; (2) the three GCEA markets are not cointegrated with either U.S. or Japan but there exists weak nonlinear relationships between these markets; and (3) result from the innovation accounting analysis reveals that the U.S. market has larger influence on the GCEA markets than the Japanese market. Additionally, Hong Kong is the most influential among the three GCEA markets.JEL Classification: G10, G14, G15Opinions and results presented in this paper are those of the authors and are not intended to represent the views, policies, or interests of Fannie Mae. This paper is not the result of Fannie Mae related research and does not use or cite Fannie Mae data sources.     

Survival

Empirical analysis of rates of return in finance implicitly condition on the security surviving into the sample. We investigate the implications of such conditioning on the time series of rates of return. In general this conditioning induces a spurious relationship between observed return and total risk for those securities that survive to be included in the sample. This result has immediate implications for the equity premium puzzle. We show how these results apply to other outstanding problems of empirical finance. Long-term autocorrelation studies focus on the statistical relation between successive holding period returns, where the holding period is of possibly extensive duration. If the equity market survives, then we find that average return in the beginning is higher than average return near the end of the time period. For this reason, statistical measures of long-term dependence are typically biased towards the rejection of a random walk. The result also has implications for event studies. There is a strong association between the magnitude of an earnings announcement and the postannouncement performance of the equity. This might be explained in part as an artefact of the stock price performance of firms in financial distress that survive an earnings announcement. The final example considers stock split studies. In this analysis we implicitly exclude securities whose price on announcement is less than the prior average stock price. We apply our results to this case, and find that the condition that the security forms part of our positive stock split sample suffices to explain the upward trend in event-related cumulated excess return in the preannouncement period.