基于跳跃-扩散KMV模型的上市公司信用风险评估

本文在传统KMV模型基础上进行改进,引入风险资产价格的跳跃因素,构建跳跃-扩散KMV模型。分别从行业属性、公司属性和公司规模三个角度,对我国126家上市公司的跳跃风险进行估计,并对其信用风险进行度量。在此基础上,以测算的违约距离为被解释变量,以经济周期、跳跃风险及反映企业自身经营情况的财务指标为解释变量,利用固定效应模型实证检验企业信用风险的影响因素。结果表明,使用跳跃-扩散KMV模型度量上市公司信用风险的效果较好,测量结果与我国实际情况较吻合;同时企业的信用风险与其自身的偿债能力和跳跃风险呈显著正相关,而与其盈利能力、成长能力、营运能力及宏观经济状况呈显著负相关。     

Pareto Index Estimation Under Moderate Right Censoring

Real claim data sometimes are censored from above at a high value induced by the sum insured. In this note we examine the behaviour of extreme-value methods in such settings and propose an adaptation of the popular Hill (1975) estimator. It is argued that the censoring typically cannot exceed 5% for an effective use of the methods suggested.     

浅析再创业中的企业资本运营

企业资本运营是一种战略行为,是以有效投资或有效理财为前提,以最佳成本和合适风险为基础,力求企业利润最大化,按照市场经济的一般规律来经营优化企业资本或生产要素的经济活动。其基本特征主要表现为：以资本导向为核心,采用价值形态管理模式,实行开放式经营,注重资本的流动性。它往往可以通过企业资产重组、买(借)”壳”上市、兼并与收购、吸收合并、债务重组和破产重组等多种多样基本模式和行为表现出来。     

Optimal investment with vintage capital: Equilibrium distributions

The paper concerns the study of equilibrium points, or steady states, of economic systems arising in modeling optimal investment with vintage capital, namely, systems where all key variables (capitals, investments, prices) are indexed not only by time but also by age. Capital accumulation is hence described as a partial differential equation (briefly, PDE), and equilibrium points are in fact equilibrium distributions in the variable of ages. A general method is developed to compute and study equilibrium points of a wide range of infinite dimensional, infinite horizon, optimal control problems. We apply the method to optimal investment with vintage capital, for a variety of data, deriving existence and uniqueness of equilibrium distribution, as well as analytic formulas for optimal controls and trajectories in the long run. The examples suggest that the same method can be applied to other economic problems displaying heterogeneity. This shows how effective the theoretical machinery of optimal control in infinite dimension is in computing explicitly equilibrium distributions. To this extent, the results of this work constitute a first crucial step towards a thorough understanding of the behavior of optimal paths in the long run.     

应该用哪一个模型来描述中国货币市场利率的动态变化

本文论证了双曲模型是描述中国货币市场利率动态变化的最佳单因子利率模型。由极大似然估计可以得到单因子利率模型的边际密度函数。双曲模型的边际密度和非参数估计得到的边际密度函数拟合较好,其表现远远优于几个常见的利率模型（CIR、CKLS和AG模型）。与较一般的Ait-Sahalia模型相比差别很小,但参数形式得到简化,似然比检验也支持这一点。双曲模型在刻画利率的均值回复特征方面还克服了AG模型的不足。     

Distribution of parallel exchange rates in African countries

This paper investigates the distribution of parallel exchange rates in African countries using exploratory data analysis techniques and model fitting. Stable laws are fitted to empirical distributions using the maximum likelihood estimation method. Empirical evidence supports the stable hypothesis these distributions are positively skewed and have tails that are much heavier than Gaussian counterparts. The stable hypothesis is further supported by the “converging variance test,” which suggests that these distributions have infinite variance.     

中国省际环境基本公共服务绩效差异分析

利用"纵横向"拉开档次评价法实证分析中国30个省级政府2002~2011年的环境基本公共服务绩效,结果表明省际差异显著。中西部大部分地区绩效整体逐年上升但总得分偏低,东部综合绩效水平明显高于中西部;环境安全性服务和环境信息性服务占综合绩效得分比重明显偏小。为此,应加大对中西部省份环境基本公共服务的财政投入,实施差异化区域性环境基本公共服务战略;同时增加对环境安全性服务和环境信息性服务的投入,提升环境基本公共服务整体水平。     

The maximum capture per unit cost location problem

This paper considers the problem of siting p new facilities of an entering firm to a competitive market so as to maximize the market share captured from competitors per unit cost. We first formulate the problem as a mixed 0-1 fractional programming model, in which we incorporate the fixed cost and transportation cost. The model can deal with the case where some demand nodes have two or more possible closest servers. We then re-formulate the problem as a 0-1 mixed integer linear program. We use a one-opt heuristic algorithm based on the Teitz-Bart method to obtain feasible solutions and compare them with the optimal solutions obtained by a branch-and-bound algorithm. We conduct computational experiments to evaluate the two algorithms. The results show that both algorithms can solve the model efficiently and the model is integer-friendly. We discuss other computational results and provide managerial insights.     

Right censoring in a discrete life model

Although there are many sophisticated models for estimation of failure rate based on censored data in continuous distributions, not much work has been done in the discrete case. We introduce a discrete model for life lengths and consider its properties. For this model, we derive the corresponding maximum likelihood estimators of the parameters under Type I and Type II right-censoring. Received May 2000     

Do overseas investments create or replace trade? New insights from a macro-sectoral study on Japan

This paper investigates the relationship between outward foreign direct investment (FDI) and exports and imports from Japan, employing an augmented standard gravity model. Several econometric techniques, including the Gamma Pseudo Maximum Likelihood estimator, are used to rectify possible problems of heteroskedasticity and zero trade flows inherent in the estimation of gravity models of trade. The major finding is that outward FDI is trade enhancing for the Japanese manufacturing industry. However, we find that whether outward FDI creates or replaces trade depends on the industry under scrutiny. Our results indicate that the complementary relationship between FDI and trade is dominant in Japanese manufacturing, especially in the food and beverages, electric machinery, primary metals, and precision machinery sectors. We find also that Japanese overseas investments substitute for imports of chemical products, and for both exports and imports of general machinery.