Comovements in volatility in the euro money market

This paper assesses the sources of volatility persistence in Euro Area money market interest rates and the existence of linkages relating volatility dynamics. The main findings of the study are as follows. Firstly, there is evidence of stationary long memory, of similar degree, in all series. Secondly, there is evidence of fractional cointegration relationships relating all series, except the overnight rate. The common long memory factor analysis points to a two-factor volatility curve. The most important factor, in terms of proportion of total variance explained, can be interpreted as a level factor (64% of total variance), while the other as a slope factor (13% of total variance). Impulse response analysis and forecast error variance decomposition finally point to non significant forward transmission of liquidity shocks.     

Gender Diversity Index. Measuring persistence

This paper deals with the analysis of the Gender Diversity Index (GDI), which is an Index developed by Solactive AG and is calculated and distributed by this provider. The index tracks the performance of developed world companies that are successfully working towards gender diversity as part of their CSR (Corporate Social Responsibility) strategy, and we measure its degree of persistence by using fractional integration or I(d) techniques. Using daily data from 8 December 2010 until 16 December 2020, the results indicate that the series is highly persistent with an order of integration lower than, though very close to 1. However, an interesting result is obtained by estimating d recursively across subsamples. The differencing parameter moves around 0.92 until 23 March 2020, with the series displaying a very small degree of mean reversion behaviour until that date. After that period, however, we observe an increase in the estimate of d, which stabilizes around 0.97 after 5 May 2020, though now the series presents evidence of a lack of mean reversion, with the shock having a permanent effect on the series. Thus, it seems that the sanitary crisis due to Covid-19 has had a clear effect in the degree of persistence of the GDI data.     

Cryptocurrencies and stock market indices. Are they related?

In this paper, we investigate the stochastic properties of six major cryptocurrencies and their bilateral linkages with six stock market indices using fractional integration techniques. From the univariate analysis, we observe that for Bitcoin and Ethereum, the unit root null hypothesis cannot be rejected; for Litecoin, Ripple and Stellar, the order of integration is found to be significantly higher than 1; for Tether, however, we find evidence in favour of mean reversion. For the stock market indices, the results are more homogeneous and the unit root cannot be rejected in any of the series, with the exception of VIX where mean reversion is obtained. Concerning bivariate results within the cryptocurrencies and testing for cointegration, we provide evidence of no cointegration between the six cryptocurrencies. Along the same lines, testing for cointegration between the cryptocurrencies and the stock market indices, we find evidence of no cointegration, which implies that the cryptocurrencies are decoupled from the mainstream financial and economic assets. The findings in this paper indicate the significant role of cryptocurrencies in investor portfolios since they serve as a diversification option for investors, confirming that cryptocurrency is a new investment asset class.     

High and low prices and the range in the European stock markets: A long-memory approach

This paper uses fractional integration techniques to examine the stochastic behaviour of high and low stock prices in Europe and then to test for the possible existence of long-run linkages between them by looking at the range, i.e., the difference between the two logged series. Specifically, monthly, weekly and daily data on the following five European stock market indices are analysed: DAX30 (Germany), FTSE100 (UK), CAC40 (France), FTSE MIB40 (Italy) and IBEX35 (Spain). In all cases, the order of integration of the range is lower than that of the original series, which implies the existence of a long-run equilibrium relationship between high and low prices. Further, multiple breaks are found in the high and low-price series but no breaks in the range, and the estimated fractional differencing parameter is positive in all cases, which represents evidence of long memory.     

Growth vs value investing: Persistence and time trend before and after COVID-19

Value investing and growth investing allow economic experts to adopt different investment strategies depending on their chosen specialty; the two investment types have been conditioned by the pandemic, changing the trend of investments and their results. This research aims to analyze the behavior and trends of the different investment strategies before and after the health crisis. We use methodologies based on fractional integration and cointegration to analyze the persistence and trend of the series and their relationship in the long run. We find that the shock is long-lived and causes a change in trend; however, we find no evidence of mean reversion. In addition, we use multivariate wavelet analysis to analyze the correlation between both time series, concluding that a growth-based investment strategy is more successful than a value-based investment strategy. We use neural networks to corroborate our results.     

On the persistence and volatility in European,American and Asian stocks bull and bear markets

In this paper we examine the statistical properties of several stock market indices in Europe, the US and Asia by means of determining the degree of dependence in both the level and the volatility of the processes. In the latter case, we use the squared returns as a proxy for the volatility. We also investigate the cyclical pattern observed in the data and in particular, if the degree of dependence changes depending on whether there is a bull or a bear period. We use fractional integration and GARCH specifications. The results indicate that the indices are all nonstationary I(1) processes with the squared returns displaying a degree of long memory behaviour. With respect to the bull and bear periods, we do not observe a systematic pattern in terms of the degree of persistence though for some of the indices (FTSE, Dax, Hang Seng and STI) there is a higher degree of dependence in both the level and the volatility during the bull periods.     

Bivariate FIGARCH and fractional cointegration

We consider the modelling of volatility on closely related markets. Univariate fractional volatility (FIGARCH) models are now standard, as are multivariate GARCH models. In this paper, we adopt a combination of the two methodologies. There is as yet little consensus on the methodology for testing for fractional cointegration. The contribution of this paper is to demonstrate the feasibility of estimating and testing cointegrated bivariate FIGARCH models. We apply these methods to volatility on the NYMEX and IPE crude oil markets. We find a common order of fractional integration for the two volatility processes and confirm that they are fractionally cointegrated. An estimated error correction FIGARCH model indicates that the preponderant adjustment is of the IPE towards NYMEX.     

Fractional cointegration and real exchange rates

This paper uses fractional integration and cointegration to model the DM-US dollar and the yen-US dollar real exchange rates in terms of both monetary and real factors, more specifically real interest rate and labour productivity differentials. We find that whilst the individual series may be integrated of order 1, their long-run relationship might have a fractionally cointegrated structure. This means that mean reversion occurs, consistently with the findings of other studies. However, it also indicates, in contrast to such studies, that the cointegrating relationship possesses long memory. In other words, the error correction term responds slowly to shocks, implying that deviations from equilibrium are long-lived. It appears that only a combination of real and monetary variables can accurately track down the movements of real exchange rates.     

Persistence and cycles in the us federal funds rate

This paper uses long-range dependence techniques to analyse two important features of the US Federal Funds effective rate, namely its persistence and its cyclical behaviour. It examines annual, monthly, bi-weekly and weekly data, from 1954 until 2017. Two models are considered. One is based on an I(d) specification with AR(2) disturbances and the other one on two fractional differencing structures, one at the zero and the other at a cyclical frequency. Thus, the two approaches differ in the way the cyclical component of the process is modelled. In both cases we obtain evidence of long memory and fractional integration with cycles repeating approximately every 8 years. The in-sample goodness-of-fit analysis supports the second specification in the majority of cases. An out-of-sample forecasting experiment also suggests that the long-memory model with two fractional differencing parameters is the most adequate one, especially over long horizons.     

Global integration and emerging stock market excess returns

This article studies the effects of the global integration process on emerging stock market excess returns in a dynamic context. I improve the existing literature in four main directions. First, I show that the average excess returns rise as the level of financial and real integration rises. Second, I find overwhelming evidence that the financial liberalizations (i.e. de jure integration) of the late 1980s and early 1990s have not been simultaneously accompanied by a de facto integration. Third, I find that the percentage of variation in emerging excess returns explained by non-traded global risk factors rises as the level of market openness rises. Last, at the country level, I show that the correlation coefficient does not represent a robust measure of integration. Results also suggest that there are substantial cross-country differences in the dynamics of the degree of financial integration.     

Economic policy uncertainty exposure and stock price bubbles: Evidence from China

We explore the impact of economic policy uncertainty exposure (hereafter, EPU exposure) on stock price bubbles. We find that there exists a significantly positive relationship between EPU exposure and stock price bubbles. This result is still significant after a series of robustness checks. Moreover, the relationship between EPU exposure and bubbles is due to retail investors' speculative trading behavior. In addition, optimistic aggregate states and firms with higher information uncertainty characteristics strengthen the EPU exposure effects. Overall, we provide unique evidence regarding the impact of uncertainty on stock prices.     

Testing for international equity market integration using regime switching cointegration techniques

Using MSCI total return index data, this paper analyses the degree of international equity market integration using modern cointegration techniques. The existence of a long run equilibrium across equity markets is important since it implies a violation of weak form market efficiency. Short run deviations away from equilibrium can be expected to reverse, thereby implying a degree of market predictability. This analysis adds to the existing literature by considering a regime switching cointegration relationship that allows for multiple structural breaks over time. The analysis provides scant evidence in favour of market integration with a single regime treatment. There is, however, significant evidence to support a two-regime Markov switching long-run equilibrium relationship that has evolved since the 1970s.     

Long memory and fractional integration in high frequency data on the US dollar/British pound spot exchange rate

This paper analyses the long-memory properties of a high-frequency financial time series dataset. It focuses on temporal aggregation and other features of the data, and how they might affect the degree of dependence of the series. Fractional integration or I(d) models are estimated with a variety of specifications for the error term. In brief, we find evidence that a lower degree of integration is associated with lower data frequencies. In particular, when the data are collected every 10 min there are several cases with values of d strictly smaller than 1, implying a mean-reverting behaviour; however, for higher data frequencies the unit root null cannot be rejected. This holds for all four series examined, namely Open, High, Low and Last observations for the US dollar/British pound spot exchange rate and for different sample periods.     

Modelling long run comovements in equity markets: A flexible approach

International equity markets linkages are characterized by nonlinear dependence and asymmetries. We investigate shifts in long run comovements in stock markets by means of an ‘interrupted’ Markov switching cointegration specification. This flexible approach allow us to study to what extent documented changes in global integration are permanent, or whether market linkages are subject to changes. Using an illustrative sample from 1980 to 2012 for USA, UK and Hong Kong stock price indices, we find evidence of interrupted cointegration across these markets between May 1997 and April 2002, which is consistent with the decoupling of stock prices from fundamentals during the dot-com bubble.     

Fractional cointegration and tests of present value models

This paper tests the validity of present value (PV) models of stock prices by employing a two-step strategy for testing the null hypothesis of no cointegration against alternatives which are fractionally cointegrated. Monte Carlo simulations are conducted to evaluate the power and size properties of this test, which is shown to outperform existing ones, and to compute appropriate critical values for finite samples. It is found that stock prices and dividends are both I(1) nonstationary series, but they are fractionally cointegrated. This implies that, although there exists a long-run relationship, which is consistent with PV models, the equilibrium errors exhibit slow mean reversion. As the error correction term possesses long memory, deviations from equilibrium are highly persistent.     

基于关联网络的经济政策不确定性全球溢出效应研究

基于关联网络视角,本文采用溢出指数方法构建2003-2018年全球经济政策不确定性的溢出网络,分别从静态和动态两个方面考察各国经济政策不确定性的溢入、溢出水平,以及全球经济政策不确定性溢出网络的结构特征。研究发现,第一,经济政策不确定性具有显著的跨国传染效应,其溢出网络呈现明显的时变特征。第二,发达国家经济政策不确定性的溢入、溢出水平高于发展中国家。第三,经济政策不确定性总溢出指数在极端事件的冲击下明显攀升,而与极端事件高度相关的国家具有更强的溢出效应。同时,各个国家经济政策不确定性的溢入水平和溢出水平的波动幅度截然不同,溢出水平的波动幅度较大而溢入水平相对平稳。第四,中国与日本、澳大利亚保持着较强的双向溢出关系,而且中国对新兴经济体,尤其是金砖国家的溢出水平较高,并主要接受韩国和欧洲发达国家的溢出影响。     

Long-Term Co-Memories and Short-Run Adjustment: Securitized Real Estate and Stock Markets

This study considers whether securitized real estate and stock markets have long-term co-memories and implications for short-term adjustment. Our results offer reasonable support for fractional cointegration (characteristic of a long memory process) between securitized real estate price, stock market price and key macroeconomic factors in some economies. The implication is that where fractional cointegration prevails, securitized real estate and common stocks are substitutable assets over the long run and these assets may not be held together in a portfolio for diversification purpose. Furthermore, short-run analysis indicates that the speed of adjustment towards the long-run equilibrium is faster for fractional integrated vector error correction model (FIVECM) than VECM as the former incorporates a long history of past cointegration residuals. Additional comparisons of the two models’ forecasting accuracy show that incorporating fractional cointegration in a VECM model improves the forecasting performance over conventional VECM models. Our results reinforce the notion that cointegration, fractional cointegration and short-run adjustment dynamics are important in understanding market integration/segmentation.     

Spot-forward cointegration,structural breaks and FX market unbiasedness

FX market unbiasedness requires spot-forward cointegration with unitary vector, or a stationary forward-premium (FP). These conditions have found mixed support, which recent research explains via FP fractional integration. An alternative explanation is breaks in spot-forward cointegration regressions, so that I apply Gregory and Hansen [Gregory, A.W., Hansen, B.E., 1996a. Residual-based tests for cointegration in models with regime shifts. Journal of Econometrics 70, 99–126; 1996b. Tests for cointegration in models with regime and trend shifts. Oxford Bulletin of Economics and Statistics 58, 555–560] models to DM, Yen and Pound data, allowing for intercept, slope, and time-trend shifts. I adapt the procedure of Bai [Bai, J., 1997. Estimation of a change point in multiple regression models. Review of Economics and Statistics 79, 551–563] to sequentially search for multiple breaks, and find evidence of cointegration with “regime-and-trend shifts” for the three currencies. Cointegration-with-breaks regressions show stationary residuals and unitary slopes across regimes, consistent with long-run unbiasedness overall. Forward-premium regressions estimated for subsamples determined by cointegration-regression break dates find support for short-run unbiasedness in some regimes but not others.     

The persistence of earnings per share

The persistence of innovations to accounting earnings per share, EPS, has important implications for equity valuation, yet it remains a largely neglected subject. This paper employs various empirical tests in order to measure the persistence of shocks to EPS for the S&P 500 index. Within the I(0)/I(1) paradigm the empirical evidence rejects the I(1) specification, supporting instead a trend-stationary representation. When fractional orders of integration are considered, the results indicate that the detrended series is long memory (d  >  0) and mean reverting (d < 1). The responses decay slowly to zero, albeit 50 quarters after an initial shock the responses remain significantly different from zero. Likewise, the variance ratio evidence suggests that the effect of a shock persists over time spans characteristic of the business cycle.

International stock market cointegration under the risk-neutral measure

This paper investigates international cointegration and financial integration among equity market indexes using index option data, providing an ex-ante analysis through investor anticipations. Daily time series of risk-neutral variance, skewness, and kurtosis are constructed for five major indexes for three sub-periods between 2003 and 2013. Fractionally cointegrated VAR models are estimated at the international level, accounting for persistence in risk-neutral moments. Our results show that there exist international equilibria in risk-neutral moments defined by several cointegrating vectors. During the 2007–2009 global crisis period, these equilibria are characterized by an increase in persistence and in the speeds of adjustment. Moreover, for risk-neutral variance and skewness, all markets are included in the equilibria and none are weakly exogenous. Outside the global crisis period, the cointegration relationship is more fragmented, especially for higher-order moments. In particular, crash and tail risks are segmented during the European debt crisis.