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Studies on African equity markets and global shocks : co-movement, contagion, and diversification
Get PDFA Doctoral thesis submitted in fulfilment of the requirements for the award of Doctor of Philosophy degree in the field of Finance
The Graduate school of Business Administration, University of the Witwatersrand, October 2016The global financial system has experienced turmoil in the past three decades, at the least. Although the shocks originate abroad, they possess some rippling effects on African economies. The essence of market integration and cross-border listings of stocks has fueled the need for African markets to be well integrated with the global economy. Despite this need, available empirical literature exploring the integration of African markets regionally, and with the rest of the world appear unclear. Moreover, the possibility of global shocks transmitting to Africa via its emerging equity markets remains underexplored. At the same time, such knowledge is critical for not only understanding the functioning of equity markets in particular, but also important for regulating the financial system in general. This thesis addresses these gaps inherent in extant literature and proffer empirical and theoretical solutions by exploring the nexus between African stock markets and global shocks. The emphasis is on contagion, co-movement, and diversification. The thesis is organized into four empirical essays, each deeply touching on specific theme (s) that form the core of the problems or research questions under investigation while employing advanced econometric techniques that underpin the modeling of asset returns.
The first essay examines the capacity of African equity markets to act as ‗hubs‘ for portfolio investors during tranquil and turbulent conditions of global equity and commodity markets. The findings posit that African stock markets provide decorrelation from commodity and global equity markets during extreme market conditions. To the extent that the results reveal the strength of African stocks in cushioning international portfolio investors in a mean-variance stand-point during market crashes, the essay helps to decay doubts in the minds of investors on the perceived lack of capacity of the continent‘s stocks to yield higher expected risk-return trade-offs during global market sell-offs. The implication of the study is that given the recent history of commodities and global stocks, fund managers around the world seeking viable alternatives to compensate for losses from commodity shocks through uncorrelated markets may consider the equity markets in Africa, albeit on account of volatility persistence, present and past market conditions, markets stability, as well as size and liquidity issues.
The second essay examines regional and global co-movement of African stock markets using the three-dimensional continuous Morlet wavelet transform methodology. The essay establishes evidence of stronger co-movements broadly narrowed to short-run fluctuations. The co-movements are time-varying and commonly non-homogeneous – with phase difference arrow vectors implying lead-lag
African Equity Markets and Global Shocks
2016
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relationships. The presence of lead-lag effects and stronger co-movements at short-run fluctuations may induce arbitrage and diversification opportunities to both local and international investors with long-term investment horizons. The findings also reveal that some African equity markets are, to a degree, segmented from volatilities of the dollar and euro exchange rates.
The third essay sheds light on whether African equity markets decoupled from, and / or converged with regional and global markets from 2003 to 2014, and analyzes the implications of that for shocks spillovers. Although there is no evidence of African markets convergence either regionally or globally, shock propagation exists in a time-varying setting. Regional markets in Africa are not just ‗shock absorbers‘ but also ‗shock transmitters‘.
In the last essay, the dependence structure and (extreme) downside developed equity markets and currency price risk spillover effects to African stock markets using value-at-risk (VaR) and conditional value-at-risk (CoVaR) based on stochastic copulas is modeled. The study finds evidence of non-homogenous weak negative dependence between stocks and the USD and EUR exchange rates. Except for Egypt, there is evidence of positive significant dependencies between all African markets and their developed counterparts. Although, evidence of both uni-directional and bidirectional causality, as well as upper and lower tail dependencies are found across the stocks and currency markets, only some minuscule evidence of downside spillover effects was recorded, albeit episodic. It is observed that propagation of shocks from the GFC had a second round effect in African stock markets. Thus, the impact of the GFC to African economies was not through the credit crunches and liquidity freezes in Phase I of the crisis, but rather through the global recession that followed into the second phase. The findings are consistent with the view that global shocks propagation to developing markets may stagger during crisis and intensify post-crisis. A practical implication from the results is that given the relatively scarce resources and levels of technological know-how available to African governments, efforts to wean the continent‟s equity markets from adverse effects of global market crashes should be geared towards plans and programmes to mitigate the shocks not at the early stages but latter stages, where the effects to Africa could be prominently felt.
Three key arguments are deduced from all the essays. First, although financial market underdevelopment seems prima-facie, to help countries isolate themselves against immediate contagion, it also reduces the ability of the real economy to cushion the impact of the crisis.
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Therefore, the argument of the thesis is that despite the common fear that a highly integrated and developed market may present fertile grounds for shock spillover, Africa must continue to pursue programmes aimed at enhancing inter and intra-regional integration. However, the degree and extent of both inter- and intra-regional integration ought to be pegged at certain optimal levels in order to reap benefits from scale economies. Such endeavours at integration will not only help in risk diversification but also help smooth the impact of shocks. The second argument is that, the proposition of the ―decoupling theory‖ i.e. returns of African equity markets and global stocks are not jointly normal during crisis periods may not be entirely tenable, empirically. Thirdly, the thesis argues that the “shift-contagion” theory may not reflect the reality for Africa, particularly during initial stages of crisis. Instead, the thesis suggests an extension and argues for a “delayed-shift contagion” theory.
Keywords: Decoupling, shift-contagion, spillover effects, CoVaR, exchange rates, commodities. JEL Classification: C40, C58, F31, F36, G10, G11, G15,GR201
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Commodities Price Cycles and their Interdependence with Equity Markets
Get PDFThis study examines time-scale connectedness between returns on African stock
markets and commodities across the energy, agriculture, metals, and beverage
markets with wavelet-based coherency, wavelet multiple cross-correlation, and
wavelet-based Sharpe ratio and generalized Sharpe ratio diversification analysis. We
find evidence of increased performance of risk-minimizing portfolios during crisis
that are broadly narrowed to long-run fluctuations (shorter scales). Such higher
performances at shorter scales suggest that, during crises, investors show some
levels of risk-aversion towards African equity investments over long term horizons.
This explains why some African markets experienced first-round effect of the global
financial crisis despite the theoretical view that African economies could potentially be
decoupled from global economic shocks during crisis. Thus, although the decoupling
phenomenon may hold for African markets during global financial crisis, if investors
decide to balance their portfolios only for the short term, the portfolio reversals may
cause serious effects to the continent. Further, of all the nine stock markets, it is only
the Ivory Coast regional bourse that maximizes the multiple correlations against the
linear combinations of the aggregate commodity indices. Lastly, the results confirm
that having a combined portfolio of commodities and equities improves performance
for different investment horizon
Commodities Price Cycles and their Interdependence with Equity Markets in Africa
No full textThis study examined time-scale connectedness between returns on African
stock markets and commodities across the energy, agriculture, metals, and
beverage markets with wavelet-based coherency, wavelet multiple crosscorrelation analysis, and wavelet-based Sharpe ratio and generalized Sharpe
ratio diversification analysis. We find evidence of increased performance of
risk-minimizing portfolios during crisis that are broadly narrowed to long-run
fluctuations (shorter scales). Such higher performances at shorter scales suggest
that, during crises, investors show some levels of risk-aversion towards African
equity investments over long term horizons. This explains why some African markets experienced first-round effect of the global financial crisis despite the
theoretical view that African economies could potentially be decoupled from global
economic shocks during crisis. Thus, although the decoupling phenomenon may
hold for African markets during global financial crisis, if investors decide to balance
their portfolios only for the short term, the portfolio reversals may cause serious
effects to the continent. Further, of all the nine stock markets, it is only the Ivory
Coast regional bourse that maximizes the multiple correlations against the linear
combinations of the aggregate commodity indices. Lastly, the results confirm that
having a combined portfolio of commodities and equities improves performance for
different investment horizons
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