The Asymmetric Impulse of the Sunshine Effect on Stock Returns and Volatilities

This study constructs a variety of GARCH models with the consideration of the generalized error distribution to analyze the relationship between the cloud cover and stock returns in Taiwan in the whole sample period (1986 to 2007) and in the two sub-sample periods (1986 to 1996 and 1997 to 2007). The data include Taiwan Stock Exchange Capitalization Weighted Stock Index and the U.S. Dow Jones Industrial Average index to proxy the impact of U.S. stock market on Taiwan’s stock market performance. The empirical finding of this study could be used to reconfirm the existence of the so-called sunshine effect. The empirical results suggest that the cloud cover has significantly negative impact on Taiwan’s stock market, especially in the low cloud cover periods. Moreover, we also examine the sunshine effect with the consideration of the first and second moments and find that when adding the two moments, the sunshine effect is not significant in the stock returns but in the stock return volatilities, which is different from outcomes in previous studies.behavior finance, stock returns, stock volatility, Sunshine effect, Threshold model

Z2 spin liquid in S=1/2 Heisenberg model on Kagome lattice: A projective symmetry group study of Schwinger-fermion mean-field states

With strong geometric frustration and quantum fluctuations, S=1/2 quantum Heisenberg antiferromagnets on the Kagome lattice has long been considered as an ideal platform to realize spin liquid (SL), a novel phase with no symmetry breaking and fractionalized excitations. A recent numerical study of Heisenberg S=1/2 Kagome lattice model (HKLM) show that in contrast to earlier studies, the ground state is a singlet-gapped SL with signatures of Z2 topological order. Motivated by this numerical discovery, we use projective symmetry group to classify all 20 possible Schwinger-fermion mean-field states of Z2 SLs on Kagome lattice. Among them we found only one gapped Z2 SL (which we call Z2[0,\pi]\beta state) in the neighborhood of U(1)-Dirac SL state, whose energy is found to be the lowest among many other candidate SLs including the uniform resonating-valentce-bond states. We thus propose this Z2[0,\pi]\beta state to be the numerically discovered SL ground state of HKLM.Comment: 12 pages, 2 figures, revtex4, published versio

Asymmetric Inflation Hedge of Housing Return: A Non-linear Vector Error Correction Approach

Conclusions of past works on the inflation hedging ability of real estate investment are not consistent. The reason for this perplexity might be the neglect of separation between high and low state of inflation, which has a great influence on empirical results. In order to examine the inflation hedging effectiveness of real estate with Taiwanese monthly housing returns and inflation, this paper uses the inflation as the threshold variable to create the nonlinear vector correction model that divides the inflation rates into high and low regime. We find robust evidence that when inflation rates are higher than 0.83% threshold value, housing returns are able to hedge against inflation, and, otherwise, they are unable. Using new methodology to discover new implications is main contribution of this study.Housing prices; Inflation; Nonlinear VECM; Taiwan

Critical theories of phase transition between symmetry protected topological states and their relation to the gapless boundary theories

Symmetry protected topological states (SPTs) have the same symmetry and the phase transition between them are beyond Landau's symmetry breaking formalism. In this paper we study (1) the critical theory of phase transition between trivial and non-trivial SPTs, and (2) the relation between such critical theory and the gapless boundary theory of SPTs. Based on examples of SO(3) and SU(2) SPTs, we propose that under appropriate boundary condition the critical theory contains the delocalized version of the boundary excitations. In addition, we prove that the boundary theory is the critical theory spatially confined between two SPTs. We expect these conclusions to hold in general and, in particular, for discrete symmetry groups as well.Comment: 16 pages, 7 figure

A measure of marketing price transmission in the rice market of Taiwan

The goal of this paper is to test whether changes in the marketing margin betweenthe farm and the retail prices can result in an asymmetric relationship between the farm and the retail prices in the rice market of Taiwan. By separating the transaction cost variation into two regimes, this paper utilizes a two-regime TVECM with the error correction term serving as the threshold variable to create a non-linear threshold model. The empirical results show that when the marketing margin is lower than the threshold value, the market system operates freely and there is feedback between the farm and retail prices. However, when the marketing margin is higher than the threshold value, the government intervenes in the market and the causality between the farm and retail prices no longer exists. The conclusions are as follows. Changes in the marketing margin can cause the asymmetric price transmission between the farm and retail prices in Taiwan’s rice markets; therefore, ignoring the effect of the marketing margin could lead to errors in the models. When the marketing margin is higher than the threshold value, the government intervenes in the market and the causality between the two prices is broken

Case Experience of Radiofrequency Ablation for Benign Thyroid Nodules: From an Ex Vivo Animal Study to an Initial Ablation in Taiwan

AbstractRadiofrequency ablation (RFA) is a minimally invasive technique, used with ultrasound or computed tomography guidance, which can produce tissue coagulation necrosis in various kinds of tumors in the human body. In the past 10 years, numerous studies about RFA in benign thyroid nodules have been published. Reviewing these studies, we noticed that the effectiveness of ablation was higher when it was performed with the “moving-shot technique” via an internally cooled electrode. A consensus statement published from the Korean Society of Radiology also suggested the moving-shot technique as a standard ablation procedure for benign thyroid nodule ablation in Korea. In Taiwan, most symptomatic benign nodules are currently treated with surgical removal. RFA for mass lesions is primarily performed for the treatment of metastatic hepatic tumors. In our case, we have attempted to introduce RFA for benign thyroid nodules in Taiwan. Because endocrinologists in Taiwan were not familiar with this technique, we adopted a stepwise approach in learning how to perform RFA. We conducted ex vivo animal ablation exercises to gain experience in setting the radiofrequency generator for the right ablation mode and appropriate power output. The thyroid nodule volume reduction rate after 1 year of follow up was approximately 50% in this case. The most important thing we learned from this trial is that we confirmed the safety of thyroid nodule ablation. To the best of our knowledge, this is the first reported study of RFA of a thyroid nodule in Taiwan