The Degree of Financial Liberalization and Aggregated Stock-return Volatility in Emerging Markets

In this study, we address whether the degree of financial liberalization affects the aggregated total volatility of stock returns by considering the time-varying nature of financial liberalization. We also explore channels through which the degree of financial liberalization impacts aggregated total volatility. We document a negative relation to the degree of financial liberalization after controlling for size, liquidity, country, and crisis effects, especially for small and medium-sized markets. Moreover, the degree of financial liberalization transmits its negative impact on aggregated total volatility through aggregated idiosyncratic and local volatilities. Overall, our results provide evidence in favor of the view that the broadening of the investor base due to the increasing degree of financial liberalization causes a reduction in the total volatility of stock returns.return volatility;financial liberalization;market integration;volatility decomposition;emerging markets

Option-Implied Volatility Measures and Stock Return Predictability

Do changes in implied volatilities (IVs) or differences among options at different spots on the volatility surface contain predictive information for future returns? The question has been asked repeatedly—and often answered in the affirmative for specific measures—but questions remain. In this article, the authors perform a comparison test on six return predictors that are all computed as differences among implied and realized volatilities and that have been proposed in the literature. The authors consider more measures, more maturities, and longer samples than earlier articles, and they include a variety of appropriate control variables. They find that the difference between at-the-money (ATM) call and put IV (CPIV) and out-of-the-money (OTM) put IV minus ATM call IV are both highly significant at the individual stock level, while a long–short portfolio strategy based on realized minus implied volatility does very well. The alternative volatility combinations are substantially less effective as return predictors

7 T renal MRI: challenges and promises

The progression to 7 Tesla (7 T) magnetic resonance imaging (MRI) yields promises of substantial increase in signal-to-noise (SNR) ratio. This increase can be traded off to increase image spatial resolution or to decrease acquisition time. However, renal 7 T MRI remains challenging due to inhomogeneity of the radiofrequency field and due to specific absorption rate (SAR) constraints. A number of studies has been published in the field of renal 7 T imaging. While the focus initially was on anatomic imaging and renal MR angiography, later studies have explored renal functional imaging. Although anatomic imaging remains somewhat limited by inhomogeneous excitation and SAR constraints, functional imaging results are promising. The increased SNR at 7 T has been particularly advantageous for blood oxygen level-dependent and arterial spin labelling MRI, as well as sodium MR imaging, thanks to changes in field-strength-dependent magnetic properties. Here, we provide an overview of the currently available literature on renal 7 T MRI. In addition, we provide a brief overview of challenges and opportunities in renal 7 T MR imaging

Prediction of left lobe hypertrophy after right lobe radioembolization of the liver using a clinical data model with external validation

In cirrhotic patients with hepatocellular carcinoma (HCC), right-sided radioembolization (RE) with Yttrium-90-loaded microspheres is an established palliative therapy and can be considered a “curative intention” treatment when aiming for sequential tumor resection. To become surgical candidate, hypertrophy of the left liver lobe to > 40% (future liver remnant, FLR) is mandatory, which can develop after RE. The amount of radiation-induced shrinkage of the right lobe and compensatory hypertrophy of the left lobe is difficult for clinicians to predict. This study aimed to utilize machine learning to predict left lobe liver hypertrophy in patients with HCC and cirrhosis scheduled for right lobe RE, with external validation. The results revealed that machine learning can accurately predict relative and absolute volume changes of the left liver lobe after right lobe RE. This prediction algorithm could help to estimate the chances of conversion from palliative RE to curative major hepatectomy following significant FLR hypertrophy

Shift-Volatility Transmission in East Asian Equity Markets

This paper attempts to provide evidence of "shift-volatility" transmission in the East Asian equity markets. By shift-volatility, we mean the volatility shifts from a low level to a high level, corresponding respectively to tranquil and crisis periods. We examine the interdependence of equity volatilities between Hong-Kong, Indonesia, Japan, Malaysia, the Philippines, Singapore, Thailand and the United States. Our main issue is whether shift-volatility needs to be considered as a regional phenomenon, or from a more global perspective. We find that the timing/spans of high volatility regimes correspond adequately to years historically documented as those of crises (the Asian crisis and the years following the 2008 crisis). Moreover, we suggest different indicators that could be useful to guide the investors in their arbitrage behavior in the different regimes: the duration of each state, the sensitivity of the volatility in a market following a change in the volatility in another market. Finally, we are able to identify which market can be considered as leading markets in terms of volatility

Real and Monetary Policy Convergence: EMU Crisis to the CFA Zone

A major lesson of the EMU crisis is that serious disequilibria result from regional monetary arrangements not designed to be robust to a variety of shocks. The purpose of this paper is to assess these disequilibria within the CEMAC, UEMOA and CFA zones. In the assessments, monetary policy targets inflation and financial dynamics of depth, efficiency, activity and size while real sector policy targets economic performance in terms of GDP growth. We also provide the speed of convergence and time required to achieve a 100% convergence. But for financial intermediary size within the CFA zone, findings for the most part support only unconditional convergence. There is no form of convergence within the CEMAC zone. The broad insignificance of conditional convergence results have substantial policy implications. Monetary and real policies which are often homogenous for member states are thwarted by heterogeneous structural and institutional characteristics which give rise to different levels and patterns of financial intermediary development. Therefore member states should work towards harmonizing cross-country differences in structural and institutional characteristics that hamper the effectiveness of monetary policies

Are Proposed African Monetary Unions Optimal Currency Areas? Real and Monetary Policy Convergence Analysis

A spectre is hunting embryonic African monetary zones: the EMU crisis. The introduction of common currencies in West and East Africa is facing stiff challenges in the timing of monetary convergence, the imperative of bankers to apply common modeling and forecasting methods of monetary policy transmission, as well as the requirements of common structural and institutional characteristics among candidate states. Inspired by the premise of the EMU crisis, this paper assesses real and monetary policy convergence within the proposed WAM and EAM zones. In the analysis, monetary policy targets inflation and financial dynamics of depth, efficiency, activity and size while real sector policy targets economic performance in terms of GDP growth at macro and micro levels. Findings suggest overwhelming lack of convergence; an indication that candidate countries still have to work towards harmonizing cross-country differences in fundamental, structural and institutional characteristics that hamper the convergence process

Are Proposed African Monetary Unions Optimal Currency Areas? Real, Monetary and Fiscal Policy Convergence Analysis

Purpose – A spectre is hunting embryonic African monetary zones: the EMU crisis. This paper assesses real, monetary and fiscal policy convergence within the proposed WAM and EAM zones. The introduction of common currencies in West and East Africa is facing stiff challenges in the timing of monetary convergence, the imperative of central bankers to apply common modeling and forecasting methods of monetary policy transmission, as well as the requirements of common structural and institutional characteristics among candidate states. Design/methodology/approach – In the analysis: monetary policy targets inflation and financial dynamics of depth, efficiency, activity and size; real sector policy targets economic performance in terms of GDP growth at macro and micro levels; while, fiscal policy targets debt-to-GDP and deficit-to-GDP ratios. A dynamic panel GMM estimation with data from different non-overlapping intervals is employed. The implied rate of convergence and the time required to achieve full (100%) convergence are then computed from the estimations. Findings – Findings suggest overwhelming lack of convergence: (1) initial conditions for financial development are different across countries; (2) fundamental characteristics as common monetary policy initiatives and IMF backed financial reform programs are implemented differently across countries; (3) there is remarkable evidence of cross-country variations in structural characteristics of macroeconomic performance; (4) institutional cross-country differences could also be responsible for the deficiency in convergence within the potential monetary zones; (5) absence of fiscal policy convergence and no potential for eliminating idiosyncratic fiscal shocks due to business cycle incoherence. Practical implications – As a policy implication, heterogeneous structural and institutional characteristics across countries are giving rise to different levels and patterns of financial intermediary development. Thus, member states should work towards harmonizing cross-country differences in structural and institutional characteristics that hamper the effectiveness of convergence in monetary, real and fiscal policies. This could be done by stringently monitoring the implementation of existing common initiatives and/or the adoption of new reforms programs. Originality/value – It is one of the few attempts to investigate the issue of convergence within the proposed WAM and EAM unions