title: The influence of the COVID-19 pandemic on the hedging functionality of Chinese financial markets

authors: Corbet, Shaen

subjects: Social Sciences

abstract: In this paper, we investigate both constant and time-varying hedge ratios in terms of the effectiveness of CSI300 index futures during the COVID-19 crisis. Using naïve, OLS and EC/ROLS strategies to estimate constant hedge ratios, results indicate that the CSI300 spot index presents decreased effectiveness using the naïve hedging strategy; however, increased effectiveness of OLS and EC hedge ratios are identified. Differential behaviour is identified when considering five newly introduced COVID-19 concept-based stock indices. Time-varying hedge ratios indicate the weakened effectiveness, ranging between 20% and 40% variance reduction. Evidence suggests that the capability of the CSI300 index futures to hedge against the risks of the COVID-19 is impaired, regardless of whether constant or time-varying hedge ratios are used. Such results provide important implications to both local and foreign investors in the Chinese stock market.

text: The influence of the COVID-19 pandemic on the hedging functionality of Chinese financial markets In this paper, we investigate both constant and time-varying hedge ratios in terms of the effectiveness of CSI300 index futures during the COVID-19 crisis. Using naïve, OLS and EC/ROLS strategies to estimate constant hedge ratios, results indicate that the CSI300 spot index presents decreased effectiveness using the naïve hedging strategy; however, increased effectiveness of OLS and EC hedge ratios are identified. Differential behaviour is identified when considering five newly introduced COVID-19 concept-based stock indices. Time-varying hedge ratios indicate the weakened effectiveness, ranging between 20% and 40% variance reduction. Evidence suggests that the capability of the CSI300 index futures to hedge against the risks of the COVID-19 is impaired, regardless of whether constant or time-varying hedge ratios are used. Such results provide important implications to both local and foreign investors in the Chinese stock market.

year: 2022

title: Identifying Mineralogical and Geochemical Vectors towards the Epithermal Au-Ag Correnso Mine, Waihi

authors: Singh, Ravinder Sardul

subjects: Correnso Deposit

abstract: The Au-Ag rich Correnso vein is a low sulphidation epithermal deposit located east of Waihi and is named after the clay mineral corrensite. Hydrothermally altered andesitic and dacitic host rocks of the Waipupu Formation, informally subdivided into Upper Andesite and Lower Andesite units, contain Au-Ag rich quartz veins. The interaction of hot, dominantly meteoric water with the host rocks causes mineralogical and geochemical changes. Hydrothermal alteration manifested as mineralogical alteration and geochemical signatures can help in identifying vectors to constrain potential areas of enhanced mineralization for exploration purposes. Hydrothermal alteration has been suggested to have potential as exploration vector for epithermal deposits in particular as alteration halos can extend up to considerable distances (Christie et al., 2001; Simpson and Mauk, 2004). 
Visual core logging, petrography, pXRF, and Aqua-Regia/2-Acid Digest (ICP-MS) analysis were used in this study to analyse and quantify alteration zonation patterns and trace element metasomatism in order to identify vectors towards the mineralisation. Results suggest a clear mineralogical and geochemical alteration zonation pattern around the vein system. The unaltered, moderately altered and highly altered rocks are often adjacent to one another, implying that hydrothermal fluids have migrated through the host rocks in a highly heterogeneous fashion. The migration of fluids is likely controlled by both primary and secondary (e.g. fault/fracture) permeability. The overall mineralogical pattern can be described as quartz ± adularia ± sericite assemblage which is similar to the adjacent deposits of the Waihi area. Alteration zonation in the host rocks consists of potassic alteration proximal to the vein system surrounded by sericitic alteration, with illite-smectite dominated argillic assemblage overprinting both alteration types. Propylitic alteration is more prominent to the outward zones and distal to the mineralisation. Geochemical analysis show enrichment of pathfinder elements such as As, As, Sb, Hg, Zn, Pb, Se, and K and depletion of Cu, Te and Se.

text: Identifying Mineralogical and Geochemical Vectors towards the Epithermal Au-Ag Correnso Mine, Waihi The Au-Ag rich Correnso vein is a low sulphidation epithermal deposit located east of Waihi and is named after the clay mineral corrensite. Hydrothermally altered andesitic and dacitic host rocks of the Waipupu Formation, informally subdivided into Upper Andesite and Lower Andesite units, contain Au-Ag rich quartz veins. The interaction of hot, dominantly meteoric water with the host rocks causes mineralogical and geochemical changes. Hydrothermal alteration manifested as mineralogical alteration and geochemical signatures can help in identifying vectors to constrain potential areas of enhanced mineralization for exploration purposes. Hydrothermal alteration has been suggested to have potential as exploration vector for epithermal deposits in particular as alteration halos can extend up to considerable distances (Christie et al., 2001; Simpson and Mauk, 2004). 
Visual core logging, petrography, pXRF, and Aqua-Regia/2-Acid Digest (ICP-MS) analysis were used in this study to analyse and quantify alteration zonation patterns and trace element metasomatism in order to identify vectors towards the mineralisation. Results suggest a clear mineralogical and geochemical alteration zonation pattern around the vein system. The unaltered, moderately altered and highly altered rocks are often adjacent to one another, implying that hydrothermal fluids have migrated through the host rocks in a highly heterogeneous fashion. The migration of fluids is likely controlled by both primary and secondary (e.g. fault/fracture) permeability. The overall mineralogical pattern can be described as quartz ± adularia ± sericite assemblage which is similar to the adjacent deposits of the Waihi area. Alteration zonation in the host rocks consists of potassic alteration proximal to the vein system surrounded by sericitic alteration, with illite-smectite dominated argillic assemblage overprinting both alteration types. Propylitic alteration is more prominent to the outward zones and distal to the mineralisation. Geochemical analysis show enrichment of pathfinder elements such as As, As, Sb, Hg, Zn, Pb, Se, and K and depletion of Cu, Te and Se.

year: 2015

title: The revitalisation roles of Māori-medium whānau

authors: Bryant, Braden

abstract: For over a century and a half, te reo Māori (the Māori language) has suffered from linguistic marginalisation, causing significant language shift to English, and, with it, generations of Māori who are unable to speak their indigenous language. While efforts since the 1970s to rebuild te reo Māori have primarily focused on educational initiatives such as kōhanga reo and kura kaupapa, there is now a move to shift the revitalisation strategy towards encouraging te reo Māori use in the home, and to rebuilding the language intergenerationally. Unfortunately, little is known about whānau perceptions regarding te reo Māori revitalisation, which is what this research investigates.

This research investigates five whānau who have committed their children to Māori-medium education. It aims to understand what influenced their decision-making around Māori-medium and what they see as the key benefits for their children. It also looks at what whānau consider to be obstacles regarding their use of te reo Māori, and at their commitment to Māori-medium education. Finally, this research aims to uncover how whānau perceive the wider revitalisation effort, and their roles in it.

The qualitative method of semi-structured interviews was used to conduct this research. The conversational nature of this method gives whānau the freedom to express their beliefs, while remaining on the main themes of this study. As the participants and themes of this research are Māori, the study used Kaupapa Māori theory and principles to guide it. This supported the overall aim of aligning with Māori aspirations, and safeguarding participants from exploitation.

This research found that perceptions of whānau often reflected the extent to which they had been affected by intergenerational language shift. Whānau still highly affected by language shift, and whose te reo Māori is less normalised in the home, prioritised te reo Māori learning at school as the key benefit of Māori-medium education. This group also faced more opposition to their Māori-medium choices from friends and whānau, and perceived their revitalisation roles to be more concerned with the immediate whānau. By contrast, the whānau who had managed to regenerate te reo Māori in their homes to a greater extent placed more emphasis on tikanga and values as benefits of Māori-medium education. They identified opposition from friends and whānau as a barrier to their promotion of te reo Māori, while also identifying their own subconscious lapses into English as a major barrier to maintaining normalised te reo Māori environments for their children. Finally, they perceived their revitalisation roles as revolving around normalising te reo Māori for their whānau and for their communities. They played important roles in establishing language domains for further use of what is their home language.

This small study shows the importance of understanding the perceptions of those who are central to the regeneration of te reo Māori because they are the key agents of successful change, and have the attitudes and skills to do so. A larger study would provide more data to support the formation of new language revitalisation strategies.

text: The revitalisation roles of Māori-medium whānau For over a century and a half, te reo Māori (the Māori language) has suffered from linguistic marginalisation, causing significant language shift to English, and, with it, generations of Māori who are unable to speak their indigenous language. While efforts since the 1970s to rebuild te reo Māori have primarily focused on educational initiatives such as kōhanga reo and kura kaupapa, there is now a move to shift the revitalisation strategy towards encouraging te reo Māori use in the home, and to rebuilding the language intergenerationally. Unfortunately, little is known about whānau perceptions regarding te reo Māori revitalisation, which is what this research investigates.

This research investigates five whānau who have committed their children to Māori-medium education. It aims to understand what influenced their decision-making around Māori-medium and what they see as the key benefits for their children. It also looks at what whānau consider to be obstacles regarding their use of te reo Māori, and at their commitment to Māori-medium education. Finally, this research aims to uncover how whānau perceive the wider revitalisation effort, and their roles in it.

The qualitative method of semi-structured interviews was used to conduct this research. The conversational nature of this method gives whānau the freedom to express their beliefs, while remaining on the main themes of this study. As the participants and themes of this research are Māori, the study used Kaupapa Māori theory and principles to guide it. This supported the overall aim of aligning with Māori aspirations, and safeguarding participants from exploitation.

This research found that perceptions of whānau often reflected the extent to which they had been affected by intergenerational language shift. Whānau still highly affected by language shift, and whose te reo Māori is less normalised in the home, prioritised te reo Māori learning at school as the key benefit of Māori-medium education. This group also faced more opposition to their Māori-medium choices from friends and whānau, and perceived their revitalisation roles to be more concerned with the immediate whānau. By contrast, the whānau who had managed to regenerate te reo Māori in their homes to a greater extent placed more emphasis on tikanga and values as benefits of Māori-medium education. They identified opposition from friends and whānau as a barrier to their promotion of te reo Māori, while also identifying their own subconscious lapses into English as a major barrier to maintaining normalised te reo Māori environments for their children. Finally, they perceived their revitalisation roles as revolving around normalising te reo Māori for their whānau and for their communities. They played important roles in establishing language domains for further use of what is their home language.

This small study shows the importance of understanding the perceptions of those who are central to the regeneration of te reo Māori because they are the key agents of successful change, and have the attitudes and skills to do so. A larger study would provide more data to support the formation of new language revitalisation strategies.

year: 2017