No description available.

Yes / The financial crisis of 2008 provides evidence for the instability of the conventional banking system. Social banks may present a viable alternative for conventional banks. This paper analyzes the performance of social banks related to the bank business model, economic efficiency, asset quality and stability by comparing social banks with banks where the difference is likely to be large, namely with the 30 global systemically important banks (G-­SIBs) of the Financial Stability Board over the period 2000-­2014. We also analyze the relative impact of the global financial crises on the bank performance. The performance of social banks and G-­SIBs is surprisingly similar.

The financial crisis of 2008 provides evidence for the instability of the conventional banking system. Social banks may present a viable alternative for conventional banks. This paper analyzes the performance of social banks related to the bank business model, economic efficiency, asset quality and stability by comparing social banks with banks where the difference is likely to be large, namely with the 30 global systemically important banks (G-SIBs) of the Financial Stability Board over the period 2000-2014. We also analyze the relative impact of the global financial crises on the bank performance. The performance of social banks and G-SIBs is surprisingly similar.

Yes / The financial crisis of 2008 provides evidence for the instability of the conventional banking system. Social banks may present a viable alternative for conventional banks. This article analyses the performance of social banks related to the bank business model, economic efficiency, asset quality, and stability by comparing social banks with banks where the difference is likely to be large, namely with the 30 global systemically important banks (G-SIBs) of the Financial Stability Board over the period 2000–2014. We also analyse the relative impact of the global financial crisis on the bank performance. The performance of social banks and G-SIBs is surprisingly similar.

Doctor of Philosophy(PhD) / It is generally accepted that tree roots can reinforce soil and improve the stability of vegetated slopes. Tree root reinforcement is also recognised in riverbanks although the contribution that the roots make to bank stability has rarely been assessed due to the reluctance of geomorphologists to examine riverbank stability by geomechanical methods that allow for the inclusion of quantified biotechnical parameters. This study investigates the interaction between alluvial soil and the roots of four southeastern Australian riparian trees. It quantifies the amount and distribution of root reinforcement present beneath typically vegetated riverbanks of the upper Nepean River, New South Wales, and examines the effect of the reinforcement on the stability of these banks. The ability of a tree to reinforce the soil is limited by the spatial distribution of its root system and the strength that the roots impart to the soil during shear. These two parameters were determined for the following four species of native riparian tree: Casuarina glauca, Eucalyptus amplifolia, Eucalyptus elata, and Acacia floribunda. The four species all exhibit a progressive reduction in the quantity of root material both with increasing depth and with increasing lateral distance from the tree stem. In the vertical direction there are two distinct zones that can be described. The first occurs from between 0 and approximately 15 % of the maximum vertical depth and consists of approximately 80 % of the total root material quantity. In this zone the root system consists of both vertical and lateral roots, the size and density of which varies between species. The second zone occurs below approximately 15 % of the maximum vertical depth and consists primarily of vertical roots. The quantity of root material in this zone decreases exponentially with depth due to the taper of individual roots. The earth reinforcement potential in terms of both geometric extent and the quantity of root material expressed as the Root Area Ratio (RAR) varies significantly from species to species. E. elata exhibited the highest values of RAR in soil zones beneath it while E. amplifolia reinforced a greater volume of soil than any of the other species examined. The increased shear resistance (Sr) of alluvial soil containing roots was measured by direct in-situ shear tests on soil blocks beneath a plantation. For three of the species (C. glauca, E. amplifolia, E. elata) Sr increased with increasing RAR measured at the shear plane, in a similar linear relationship. The shear resistance provided by A. floribunda roots also increased with increasing RAR at the shear plane but at a much greater rate than for the other three species. This is attributable to A. floribunda’s greater root tensile strength and therefore pull-out resistance, as well as its smaller root diameters at comparative RARs which resulted in a greater proportion of roots reaching full tensile strength within the confines of the test. Tree roots fail progressively in this system. Therefore determining the increased shear strength from the sum of the pull-out or tensile strengths of all individual roots and Waldron’s (1977) and Wu et al’s (1979) simple root model, would result in substantial over estimates of the overall strength of the soil-root system. The average difference between Sr calculated in this manner and that measured from direct in-situ shear tests is 10.9 kPa for C. glauca, 19.0 kPa for E. amplifolia, 19.3 kPa for E. elata, and 8.8 kPa for A. floribunda. A riverbank stability analysis incorporating the root reinforcement effect was conducted using a predictive model of the spatial distribution of root reinforcement beneath riparian trees within the study area. The model is based on measurements of juveniles and observations of the rooting habits of mature trees. It indicates that while the presence of vegetation on riverbank profiles has the potential to increase stability by up to 105 %, the relative increase depends heavily on the actual vegetation type, density, and location on the bank profile. Of the species examined in this study the greatest potential for improved riverbank stability is provided by E. amplifolia, followed by E. elata, A. floribunda, and C. glauca. The presence of trees on banks of the Nepean River has the potential to raise the critical factor of safety (FoS) from a value that is very unstable (0.85) to significantly above 1.00 even when the banks are completely saturated and subject to rapid draw-down. It is likely then that the period of intense bank instability observed within this environment between 1947 and 1992 would not have taken place had the riparian vegetation not been cleared prior to the onset of wetter climatic conditions. Typical ‘present-day’ profiles are critically to marginally stable. The introduction of vegetation could improve stability by raising the FoS up to 1.68 however the selection of revegetation species is crucial. With the placement of a large growing Eucalypt at a suitable spacing (around 3-5 m) the choice of smaller understorey trees and shrubs is less important. The effect of riparian vegetation on bank stability has important implications for channel morphological change. This study quantifies the mechanical earth reinforcing effect of some native riparian trees, thus allowing for improved deterministic assessment of historical channel change and an improved basis for future riverine management.

Doctor of Philosophy(PhD) / It is generally accepted that tree roots can reinforce soil and improve the stability of vegetated slopes. Tree root reinforcement is also recognised in riverbanks although the contribution that the roots make to bank stability has rarely been assessed due to the reluctance of geomorphologists to examine riverbank stability by geomechanical methods that allow for the inclusion of quantified biotechnical parameters. This study investigates the interaction between alluvial soil and the roots of four southeastern Australian riparian trees. It quantifies the amount and distribution of root reinforcement present beneath typically vegetated riverbanks of the upper Nepean River, New South Wales, and examines the effect of the reinforcement on the stability of these banks. The ability of a tree to reinforce the soil is limited by the spatial distribution of its root system and the strength that the roots impart to the soil during shear. These two parameters were determined for the following four species of native riparian tree: Casuarina glauca, Eucalyptus amplifolia, Eucalyptus elata, and Acacia floribunda. The four species all exhibit a progressive reduction in the quantity of root material both with increasing depth and with increasing lateral distance from the tree stem. In the vertical direction there are two distinct zones that can be described. The first occurs from between 0 and approximately 15 % of the maximum vertical depth and consists of approximately 80 % of the total root material quantity. In this zone the root system consists of both vertical and lateral roots, the size and density of which varies between species. The second zone occurs below approximately 15 % of the maximum vertical depth and consists primarily of vertical roots. The quantity of root material in this zone decreases exponentially with depth due to the taper of individual roots. The earth reinforcement potential in terms of both geometric extent and the quantity of root material expressed as the Root Area Ratio (RAR) varies significantly from species to species. E. elata exhibited the highest values of RAR in soil zones beneath it while E. amplifolia reinforced a greater volume of soil than any of the other species examined. The increased shear resistance (Sr) of alluvial soil containing roots was measured by direct in-situ shear tests on soil blocks beneath a plantation. For three of the species (C. glauca, E. amplifolia, E. elata) Sr increased with increasing RAR measured at the shear plane, in a similar linear relationship. The shear resistance provided by A. floribunda roots also increased with increasing RAR at the shear plane but at a much greater rate than for the other three species. This is attributable to A. floribunda’s greater root tensile strength and therefore pull-out resistance, as well as its smaller root diameters at comparative RARs which resulted in a greater proportion of roots reaching full tensile strength within the confines of the test. Tree roots fail progressively in this system. Therefore determining the increased shear strength from the sum of the pull-out or tensile strengths of all individual roots and Waldron’s (1977) and Wu et al’s (1979) simple root model, would result in substantial over estimates of the overall strength of the soil-root system. The average difference between Sr calculated in this manner and that measured from direct in-situ shear tests is 10.9 kPa for C. glauca, 19.0 kPa for E. amplifolia, 19.3 kPa for E. elata, and 8.8 kPa for A. floribunda. A riverbank stability analysis incorporating the root reinforcement effect was conducted using a predictive model of the spatial distribution of root reinforcement beneath riparian trees within the study area. The model is based on measurements of juveniles and observations of the rooting habits of mature trees. It indicates that while the presence of vegetation on riverbank profiles has the potential to increase stability by up to 105 %, the relative increase depends heavily on the actual vegetation type, density, and location on the bank profile. Of the species examined in this study the greatest potential for improved riverbank stability is provided by E. amplifolia, followed by E. elata, A. floribunda, and C. glauca. The presence of trees on banks of the Nepean River has the potential to raise the critical factor of safety (FoS) from a value that is very unstable (0.85) to significantly above 1.00 even when the banks are completely saturated and subject to rapid draw-down. It is likely then that the period of intense bank instability observed within this environment between 1947 and 1992 would not have taken place had the riparian vegetation not been cleared prior to the onset of wetter climatic conditions. Typical ‘present-day’ profiles are critically to marginally stable. The introduction of vegetation could improve stability by raising the FoS up to 1.68 however the selection of revegetation species is crucial. With the placement of a large growing Eucalypt at a suitable spacing (around 3-5 m) the choice of smaller understorey trees and shrubs is less important. The effect of riparian vegetation on bank stability has important implications for channel morphological change. This study quantifies the mechanical earth reinforcing effect of some native riparian trees, thus allowing for improved deterministic assessment of historical channel change and an improved basis for future riverine management.

abstract: This research examines lateral separation zones and sand bar slope stability using two methods: a parallelized turbulence resolving model and full-scale laboratory experiments. Lateral flow separation occurs in rivers where banks exhibit strong curvature, for instance canyon rivers, sharp meanders and river confluences. In the Colorado River, downstream Glen Canyon Dam, lateral separation zones are the principal storage of sandbars. Maximum ramp rates have been imposed to Glen Canyon Dam operation to minimize mass loss of sandbars. Assessment of the effect of restricting maximum ramp rates in bar stability is conducted using multiple laboratory experiments. Results reveal that steep sandbar faces would rapidly erode by mass failure and seepage erosion to stable slopes, regardless of dam discharge ramp rates. Thus, continued erosion of sand bars depends primarily of turbulent flow and waves. A parallelized, three-dimensional, turbulence resolving model is developed to study flow structures in two lateral separation zones located along the Colorado River in Grand Canyon. The model employs a Detached Eddy Simulation (DES) technique where variables larger than the grid scale are fully resolved, while Sub-Grid-Scale (SGS) variables are modeled. The DES-3D model is validated using ADCP flow measurements and skill metric scores show predictive capabilities of simulated flow. The model reproduces the patterns and magnitudes of flow velocity in lateral recirculation zones, including size and position of primary and secondary eddy cells and return current. Turbulence structures with a predominately vertical axis of vorticity are observed in the shear layer, becoming three-dimensional without preferred orientation downstream. The DES-3D model is coupled with a sediment advection-diffusion formulation, wherein advection is provided by the DES velocity field minus particles settling velocity, and diffusion is provided by the SGS. Results show a lateral recirculation zone having a continuous export and import of sediment from and to the main channel following a pattern of high frequency pulsations of positive deposition fluxes. These high frequency pulsations play an important role to prevent an oversupply of sediment within the lateral separation zones. Improved predictive capabilities are achieved with this model when compared with previous two- and three-dimensional quasi steady and steady models. / Dissertation/Thesis / Appendix C Video 3.1 / Appendix C Video 3.2 / Appendix C Video 3.3 / Appendix C Video 3.4 / Appendix C Video 3.5 / Appendix C Video 3.6 / Appendix C Video 3.7 / Appendix F Video 4.1.a / Appendix F Video 4.1.b / Appendix F Video 4.2 / Doctoral Dissertation Geography 2015

Mortgage loans are the major assets securitised by South African banks. Arguments from the literature indicate that the use of securitisation as an instrument for regulatory arbitrage weakened banks’ soundness and caused, at least partially, the 2007-2008 Global Financial Crisis. In this regard, financial institutions continually took advantage of the loopholes in the Basel regulation, principally that of Basel I. Undertaken from both the empirical and theoretical angles, this thesis investigated whether regulatory capital arbitrage under Basel II and III regulations, was a driver of mortgage loans securitisation by South African banks. Additionally, the effect of mortgage loans securitisation on the South African banks’ stability was analysed. Furthermore, the project built upon the case of mortgage loans securitisation to deepen the insight on banks’ behaviour towards risk, by considering a rare contractual relationship where banks are regarded as agents acting on behalf of regulators. The theoretical examination was carried out by means of perspectives from Agency and Institutional Theories. The South African banking system is essentially monopolistic with five banks holding more than 90% of total assets, out of which four, with 70% of the assets, consistently report outstanding volume of mortgage loans securitised. Based on the data collected from these four major banks, this research project is the first in many regards. It involves an emerging economy, considers the influence of both Basel II and III regulations, covers the period 2008 to 2015, and focuses on well-capitalised banks exclusively. Moreover, it extends regulatory capital arbitrage analysis to the evidence of loans expansion, includes CAMELS as bank stability proxy and brings in Agency Theory and Institutional Theory to explain banks’ behaviour with regards to risk in this particular context. In contrast, other studies were concentrated on Europe and America, mostly under Basel I, limited to one or two baseline models for regulatory capital arbitrage and often only the Z-score measure was used for bank stability. In three major steps, this study first employed the Ordinary Least Squares statistical methodology to test the capital arbitrage theory of securitisation and other of its features whereby it causes the decrease of capital with little or no reduction of risk. The estimation results indicated that securitisation of mortgage loans lessened South African banks’ regulatory capital, increased their overall risk level and moreover, suggested that the proceeds from securitisation were used to expand their loans portfolios. These outcomes tentatively imply that South African banks securitise mortgage loans for regulatory capital arbitrage. The second step explored the impact of securitisation of mortgage loans on South African banks’ stability. Two different measures of bank stability were involved: the CAMELS and the Z-score. CAMELS stands for C: capital (leverage ratio and not the regulatory capital); A: assets quality; M: management efficiency; E: earning; L: liquidity; and S: sensitivity to market risk (interest risk). The Two Stage Least Squares and the Ordinary Least Squares statistical methods were used respectively for the analysis of the relationship between the two bank stability indicators and the outstanding volume of mortgage securitised. The empirical results from CAMELS showed that mortgage loans securitised negatively affected the level of capital proxied by the leverage ratio, eroded assets quality and increased South African banks’ overall costs. However, they had a positive effect on South African banks’ profit, they seemed to be an additional source of liquidity and represented a useful tool to curtail market risk sensitivity, especially the interest risk as they increased net interest income. With regards to the analysis with the Z-score, the results indicated a negative impact of mortgage securitised on South African banks’ stability. The outcome remained unchanged when retained interests in the form of subordinated loans were included in the analysis, but retained interest had a positive influence on the Z-score. The last step of this study pertained to the theoretical analysis based on the concepts of Agency Theory and Institutional Theory. Acting as regulators’ agents in an agency relationship, the simple model of Agency Theory in its extended form explained that South African banks were first and foremost risk-taking players. They were more interested in the risk/reward trade-off in their decision-making attitude towards risk than pursuing the regulators’ goal of the stability of the banking system. In that sense, it was not a surprise that they engaged in regulatory capital arbitrage despite knowing that it was risky but could provide gains in liquidity and profit. In addition to goals conflict, Agency Theory indicated asymmetry of information between banks and regulators as the indirect origin of regulatory capital arbitrage, where the opacity of banks’ activities, such as securitisation, rendered regulations ineffective and thus easy to shirk. Furthermore, it was found that the essentials of the behaviour-oriented contract suggested by the theory as the optimal contract, were already included in the formulation of the latest Basel Accords. However, the researcher believes that one key element, which is the reward or compensation that should benefit the banks (the agent) when they abide by the terms of the contract, is missing. Regulators should therefore include incentives in the regulations and combine the behaviour and outcome-oriented contracts to optimize their relationship with banks even though, as explained by the theory, the outcome of bank stability will remain partially uncertain due to uncontrollable factors such as the economic conditions. The concept of legitimacy, from Institutional Theory, explicated that banks’ legitimacy came from their ability to comply with the regulations. From this stance, the results suggested that regulatory capital arbitrage seemed instead to undermine the legitimacy of South Africa banks well-capitalised position.

Yes / This study proposes an optimisation-based “benefit-of-the-doubt” (BoD) methodological framework for developing a new multidimensional index of bank stability. The proposed index has the ability to serve as a potent policy tool that overcomes the downsides of accounting- and market-based measures of bank stability. This data-driven approach generates endogenous weights for aggregating bank stability indicators and dimensions. Further, we integrate the BoD framework with a metafrontier approach, which we call a “meta-BoD framework”. The final outcomes of the suggested framework go beyond a scalar measure of bank stability and provide the unique weighting matrix that offers valuable policy-relevant insights about the most precarious areas of stability that require the attention of management and regulators for both micro- and macro-level policy interventions. In addition, it draws insightful information about the instability gaps across heterogenous bank groups. The study presents an illustrative example of the proposed framework to obtain a bank stability index using the dataset of 76 Indian banks operating between 2014 and 2018. The bank stability index is made up of 14 financial ratio indicators covering five dimensions of stability: asset quality, management efficiency, capital adequacy, profitability and liquidity. The findings offer the detailed information required for comprehending the evolution of bank stability and assessing instability gaps across bank groups. / The full-text of this article will be released for public view at the end of the publisher embargo on 5 Jun 2024.

This research examines the impact of certain bank-specific variables on bank stability in Ghana, in the context of the existing regulatory structures. The thesis examines this issue along two main themes. The first part of this study examines whether two of the commonly used measures of banking stability, the CAMELS and the Z-Score, provide similar or different results in assessing the stability of banks in Ghana. The results of this study show that the use of the CAMELS and the Z-score measures could lead to different outcomes in terms of bank stability in Ghana. This suggests that the traditional micro-prudential CAMELS framework should be complemented with the Z-score which inherently has both micro and macro-prudential characteristics of signaling weaknesses in bank stability, and to enhance the management of bank stability. The second part of the study examines the impact of some bank-specific variables on bank stability. Using the panel data approach, the results show that while bank size, regulatory governance, regulatory independence and origin impact significantly on the stability score, there was no significant impact in terms of interbank borrowing and non-performing loans. Further analysis using the Blinder –Oaxaca decomposition also suggests that foreign banks in Ghana exhibit relatively higher levels of stability compared to local banks. The policy implications of these findings suggest that the liberalisation of the banking sector should be accompanied by an effective micro- and macro-prudential supervisory regime in order to manage the stability of the constituent banks and the banking sector as a whole.