The core of the inductive limit of a direct system of economies with a communication structure

This paper studies direct systems of finite, that is with finitely many agents, communication structures, finite (balanced and superadditive) NTU games and finite economies. The inductive limit of such a system is again a communication structure, an NTU game or an economy, this time possibly with infinitely many agents. As a matter of fact, each infinite communication structure, each infinite NTU game and each infinite economy, is the inductive limit of a direct system of finite communication structures, finite NTU games and finite economies. A communication game is an NTU game with a communication structure on the set of players. To each economy, there corresponds a balanced and superadditive NTU game. To each economy with a communication structure on the set of agents, there corresponds a communication game. In the paper it is proved that the core of the inductive limit of a direct system of communication games is not empty and in fact the intersection of the cores of the finite communication games of the direct system. It follows that each infinite economy (with or without a communication structure on the set of agents) has a nonempty core. A direct system of economies is a generalisation of the Debreu and Scarf [Debreu, G., Scarf, H. A limit theorem on the core of an economy, International Economic Review 4, pp. 235–246.] example of `replica economies'. The proof of the nonemptiness of the core of the inductive limit of a direct system of economies is along the lines of the proof by Debreu and Scarf. As by-product it is shown that an NTU game is totally balanced if and only if all its finite subgames are balanced.     

关于林权抵押贷款贷款期限的探讨

从林农经济利益角度出发,运用经济分析和数学推理的方法,引入生物生长模型,在分析林木蓄积、林木资产价值和贷款资金的时间价值基础上,确立合理的采伐时间和最佳的采伐时间,进而确立可行的贷款期限和最低贷款期限、最佳的贷款期限。以马尾松为例,进行实际计算分析,得出可行的贷款年限为8～19年,8年为最低贷款年限,19年为最佳的贷款年限。     

The impact of trading restrictions and margin requirements on stock index futures

Stock index futures in Chinese market have consistently diverged from their theoretical values. In this paper, we try to provide some explanations by proposing an equilibrium model. Although the model itself does not provide analytical solutions, it enables us to conduct extensive numerical studies and compare them with our empirical results on two major Chinese market indices, CSI300 and SSE50. Our results show that the divergence of stock index futures prices from their theoretical values may be due to various trading and regulatory constraints, such as position limits and margin requirements, which play significant roles in Chinese market.     

Tail risk under price limits

This study investigates tail risk dynamics when price limits exist in stock markets, which have not been examined in the previous literature. We present the expected value of tail risk under price limits and then analyze the extent to which such limits affect Korean stock markets when they are eased gradually. The main results are threefold. First, tail risk is seriously underestimated in stock markets with a price limit system. Second, tail risk is a significant risk factor in determining asset prices if price limits are above a certain level (15%). Lastly, related to the Korean economy, tail risk has predictive power to the future stock returns when the price limit is more than 15%. In particular, tail risk has no predictive power until price limits are relaxed to 15%, implying that caution is needed when the effects of tail risk are analyzed in countries where price limits exist.     

我国跨境电商通关监管生态系统演化创新的动力机制

基于商业生态系统在互联网背景下的平台化原理,可解释我国跨境电商通关监管系统演化和监管模式创新的动态过程与动力机制。研究发现,跨境电商监管生态系统结构经历了中心-辐射型双边监管系统、规则网络型多边监管系统、共生型复杂自组织监管系统的演化过程,推动了不同阶段的监管模式创新。系统结构优化和系统能力提升是通关监管生态系统创新与升级的关键,平台正确的战略选择和不断叠加的外部网络效应共同推动了监管系统升级和监管模式创新。对比现状可知,跨境电商监管模式创新过程中仍存在数据的精确统计、监管的跨区域协同、通关流程中的瓶颈环节、知识产权监管和产品质量追溯等难题。据此,应加快构建规范化、法治化、便利化的新型监管体系,依托大数据分析等新兴技术,使通关监管"前推后移",并通过"微创新"不断优化通关监管流程。     

Bank executive pay limits and discretionary loan loss provisions: Evidence from China

This paper investigates the impact of bank executive pay limits on discretionary loan loss provisions (DLLPs) in the context of a large emerging economy, such as that of China. We find that a bank executive pay limit primarily aimed at temporarily suspending stock option incentive plans leads to a significant rise in income-decreasing DLLPs, whereas a pay limit implemented to restrict the total emoluments leads to a significant decline in income-increasing DLLPs. Moreover, the degree of the impact of pay limits on bank DLLPs varies with CEOs’ personal characteristics and bank executive perquisites.     

A central limit theorem for the Hellinger loss of Grenander‐type estimators

We consider Grenander‐type estimators for a monotone function , obtained as the slope of a concave (convex) estimate of the primitive of λ. Our main result is a central limit theorem for the Hellinger loss, which applies to estimation of a probability density, a regression function or a failure rate. In the case of density estimation, the limiting variance of the Hellinger loss turns out to be independent of λ.     

一种基于自适应网格剖分的协方差交集融合新算法

针对分布式航迹融合问题，提出了一种基于自适应网格剖分的协方差交集融合新算法。首先，自适应计算网格剖分误差上限；其次，利用网格剖分法求出局部航迹协方差椭圆的交集；最后，利用交集中心求出融合航迹估计值。通过仿真试验，该算法能自适应估计网格剖分步长上限，提高融合精度。     

Testing the effect of technical analysis on market quality and order book dynamics

We find empirical support for the theoretical finding in agent-based models of limit order book markets that the effect of technical trading on market quality is not positive. When signals occur, technical traders lower liquidity as proxied by the relative spread, the effective spread, the realized spread, the dispersion and the slope in the order book. Technical trading is also found to be accompanied by rising volatility. There is overall strong empirical support against the hypothesis that technical trading has no effect on order book dynamics.     

中国再保险加入WTO分析

中国已成为世贸组织成员 ,国内再保险市场结构将发生重大的调整 ,民族再保险主体的体制以及保险产业发展政策将受到全面挑战。作者就我国再保险业的发展状况、存在的问题、加入WTO后所面临的机遇和挑战以及如何构建符合我国国情的再保险市场提出了一些建议。