中国农业保险现状分析

农业是相对弱势产业,农业保险对于分散农业风险至关重要。目前,我国的农业风险损失逐年增大,作为重要风险保障机制的农业保险却不断萎缩。本文通过对中国农业保险现状的分析,找出我国农业保险现阶段存在的问题,并分析了造成这些问题的原因。从而进一步探讨出促进当前中国农业探险发展的建议,认为只有对现有的农业保险机制进行改革,才能最终建立起具有中国特色的农业保险体制。     

新型城镇化与都市农业发展耦合关系及时序特征研究以武汉市为例

[目的]新型城镇化引致都市农业实现高质量发展,都市农业发展倒逼新型城镇化协同高效推进;探究新型城镇化与都市农业发展的耦合互动关系,对加快推动两系统协调发展具有重要意义。[方法]文章基于2006—2017年武汉市新型城镇化与都市农业发展水平的评价指标测度数据,运用耦合协调度模型定量分析了新型城镇化与都市农业发展的耦合关系。[结果](1)新型城镇化与都市农业总体发展水平均呈上升态势,耦合关系显著;(2)两者耦合度C值在0.490左右变化浮动,2008年和2013年耦合度出现最低值和最高值,分别为0.475和0.500;(3)耦合协调度D值处在0.290～0.627,耦合协调等级从中度失调转变为初级协调阶段,且时序演变呈现出小幅波动性、差异性和阶段性特征。[结论]武汉市新型城镇化与都市农业发展水平的耦合协调程度处于不断完善中,时序特征变化明显。为此,武汉市应坚持贯彻实施"以人为本"及城乡融合发展的新型城镇化发展道路,挖掘农业的多种功能以打造都市农业高质量发展的升级版,强化政策扶持的支持力度以保障新型城镇化与都市农业耦合协调发展。     

Improving market timing of time series momentum in the Chinese stock market

ABSTRACT

This paper is the first study to present firm-level evidence that the time-series momentum (TSMOM) strategies with look-back-period k of 10 to 200 days outperform the buy-and-hold strategy (BH) on individual stocks in the Chinese stock market. We document that the optimal k* generating the best performance is different across assets and varies over time. We hence propose a model to predict the asset-specific and time-dependent k*, and examine the performance of the TSMOM strategies with the predicted k*. Our analysis shows that using the time-varying predicted k* substantially improves the predictability of the TSMOM strategies. Our new model and findings shed the light on trading strategy for both academia and applied investment practitioners.     

Forecasting stock returns: A predictor-constrained approach

We develop a novel method to impose constraints on univariate predictive regressions of stock returns. Unlike previous approaches in the literature, we implement our constraints directly on the predictor, setting it to zero whenever its value falls within the variable’s past 24-month high and low. Empirically, we find that relative to standard unconstrained predictive regressions, our approach leads to significantly larger forecast gains. We also show how a simple equal-weighted combination of our constrained forecasts leads to further improvements in forecast accuracy, generating forecasts that are more accurate than those obtained using current constrained methods. Further analysis confirms that these findings are robust to the presence of model instabilities and structural breaks.     

On American VIX options under the generalized 3/2 and 1/2 models

In this paper, we extend the 3/2 model for VIX studied by Goard and Mazur and introduce the generalized 3/2 and 1/2 classes of volatility processes. Under these models, we study the pricing of European and American VIX options, and for the latter, we obtain an early exercise premium representation using a free‐boundary approach and local time‐space calculus. The optimal exercise boundary for the volatility is obtained as the unique solution to an integral equation of Volterra type. We also consider a model mixing these two classes and formulate the corresponding optimal stopping problem in terms of the observed factor process. The price of an American VIX call is then represented by an early exercise premium formula. We show the existence of a pair of optimal exercise boundaries for the factor process and characterize them as the unique solution to a system of integral equations.     

How do crazy rich Asians perceive sustainable luxury? Investigating the determinants of consumers’ willingness to pay a premium price

Motivated by the increasing media coverage of environmental disasters and growing evidence of humans’ detrimental impacts on the natural environment, the key aim of this study was to examine consumer interest in buying sustainable luxury products. Rooted in the Value-Belief-Norm (VBN) theory, a research framework incorporating pro-environmental self-identity (PSI), consumer pro-environmental values (CPV), engagement, and willingness to pay a premium price (WPP) was proposed. To better understand the sustainable behavior of consumers, this study modelled myopia as a personality trait that moderates the aforementioned relationships. Partial least squares path modelling (PLSPM) was employed to analyze data collected from 296 Chinese consumers who had purchased luxury fashion products. The results highlighted the influential role of CPV in shaping both consumer engagement and WPP, surpassing the impact of PSI. Also, the study established the positive effect of engagement on WPP and confirmed its mediating role in the relationship between CPV and WPP. The incorporation of myopia as a moderator further enhanced the explanatory power of the VBN theory in understanding sustainable consumption evaluations. The findings revealed that the positive links between PSI, CPV, engagement, and WPP were particularly pronounced among non-myopic consumers, suggesting that a clear vision of long-term consequences strengthens the connections between these constructs. These findings offer valuable insights to both academics and practitioners, particularly in the realm of luxury fashion brands within Chinese culture. They provide a foundation for designing targeted marketing communication strategies that effectively leverage and cultivate consumers' pro-environmental self-identities and values. By aligning brand messaging with these values, luxury fashion brands can enhance consumer engagement and foster a willingness to invest in sustainable products. Ultimately, this study contributes to the growing body of knowledge on sustainable consumption and offers practical implications for promoting environmentally responsible choices in the luxury fashion industry.     

Beta dispersion and market timing

The beta dispersion, which is the spread of betas on a stock market, can be interpreted as a measure of market vulnerability. This study examines the economic idea of the beta dispersion and its application as a market return predictor. Based on the empirical beta dispersion observed in the US equity market, the study develops measures to predict future market returns. These dispersion measures have substantial predictive power for future market movements. Moreover, I show that the information content of beta dispersion can be successfully exploited by market timing strategies with the help of distributional regressions. The innovative application of this novel approach of modeling the relationship between multiple variables appears to be quite useful for timing strategies.     

Disaggregation and the equity premium puzzle

Standard macroeconomic models cannot explain why stocks so greatly outperform bonds. However, this result depends on the use of aggregate consumption data. If markets are incomplete, then a representative agent might not exist and it is necessary to use consumption data at the household rather than aggregate level. In the household data, I fail to reject the Euler equation when the coefficient of relative risk aversion is as low as 2.7–3.8. This result is robust in a very general framework and I prove that many of the tests used in the literature are biased.     

Decomposing the VIX: Implications for the predictability of stock returns

The VIX index is not only a volatility index but also a polynomial combination of all possible higher moments in market return distribution under the risk-neutral measure. This paper formulates the VIX as a linear decomposition of four fundamentally different elements: the realized variance (RV), the variance risk premium (VRP), the realized tail (RT), and the tail risk premium (TRP), respectively. Using an innovative and nonparametric tail risk measure, we find that approximately one-third of the VIX's formation is attributed to the TRP. In addition to VRP, RT and TRP are crucial components for predicting future returns on equity portfolios.     

Portfolio concentration and fund manager performance

This research examines the relationships among portfolio concentration, fund manager skills, and fund performance in Taiwan's equity mutual fund industry, yielding several empirical findings as follows. First, after controlling for other factors, concentrated equity funds tend to have smaller net asset values, larger fund flows, higher turnover rates, and a younger age and prevail in smaller fund families. Second, concentrated fund managers buy and sell stocks more smartly based on economic trends or market factors than do diversified fund managers, i.e., they have better market‐timing abilities. Third, only partial evidence supports the premise that concentrated equity funds have better next‐quarter risk‐adjusted performances than do diversified ones, as these fund managers' skills positively correlate to risk‐adjusted fund performance. Fourth, fund managers who have better stock‐picking abilities and intensively invest in certain industries generally exhibit better Carhart's alpha in the next quarter than do other fund managers. Fifth, fund managers' stock‐picking abilities more closely relate to long‐term performance than do their market‐timing abilities. Lastly, positive performance persistence is much stronger than negative performance persistence, but concentrated funds do not have stronger performance persistence than do diversified funds.