Sustainable development. With or without mankind?

The author challenges the conventional wisdom that the main risk to Western development is environmental degradation caused by mankind. Concern over the greenhouse effect and global warming have more to do with millenium fever than reality. There is still very little evidence to suggest that these environmental phenomena result from human activity. What we do know is that there have been major cyclical fluctuations throughout history. The author cautions against implementing ‘scientistic’ policies in the face of such doubts, just because it is trendy to do so.     

A forecasting comparison of some var techniques

Higher dimensional multivariate time series models suffer from the problem of over-parametrisation which impairs their forecasting performance. Starting from such unrestricted vector autoregressive models the paper discusses two ways to cope with this difficulty. The first approach reduces the number of free parameters by applying a subset modelling strategy. The second approach takes a Bayesian point of view by formulating ‘priors’ which are then combined with sample information, but leaving the original specification unaltered. Using Austrian quarterly macroeconomic time series a comparative study is undertaken by running alternative forecasting exercises. Both methods improve out-of-sample forecasting performance substantially at the cost of some bias in ex-post simulations. Comparing the ex-ante predictions of the two approaches, the former does better at short horizons whereas the latter gains as the forecast horizon lengthens.     

基于ISM的可达矩阵的简便算法

解释结构模型化技术是最基本、最具特色的系统结构模型化技术,求可达矩阵又是建立递阶结构模型(ISM)中最重要的一步,本文基于ISM有向图,根据布尔代数运算规则,阐述一种更简便的由邻接矩阵求可达矩阵的新算法。本文与Warshall算法作对比,体现出该新算法的简便之处。该算法以后也可以实现计算机化。     

低地板有轨电车可靠性分配及应用

可靠性分配时保证低地板有轨电车整车可靠性水平的重要任务之一。比例组合法多用于平台化设计的设备或系统可靠性分配工作,首先明确故障定义,进行功能分解,建立模型,最后将指标分配至各子系统,使得设计人员和供应商明确可靠性设计要求。     

Position limit for the CSI 300 stock index futures market

The aim of this study was to find the optimal position limit for the Chinese stock index (CSI) 300 futures market. A low position limit helps to prevent price manipulations in the spot market, and thus keeps the magnitude of instantaneous price changes within the tolerance range of policymakers. However, setting a position limit that is too low may also have negative effects on market quality. We propose an artificial limit order market with heterogeneous interacting agents to examine the impact of different levels of position limits on market quality, measured as liquidity, return volatility, efficiency of information dissemination, and trading welfare. The simulation model is based on realistic trading mechanisms, investor structure, and order submission behavior observed in the CSI 300 futures market.Our results show that on the basis of the liquidity status in September 2010, raising the position limit from 100 to 300 could significantly improve market quality and at the same time keep the maximum absolute price change per 5 s below the 2% tolerance level. However, the improvement becomes only marginal if the position limit is further increased beyond 300. Therefore, we believe that raising the position limit to a moderate level can enhance the functionality of the CSI 300 futures market, which should benefit the development of the Chinese financial system.     

我国企业年金税惠政策的成本和收益精算评估

企业年金个人所得税递延政策于2014年1月1日开始实施,政策调整必然会带来相应的成本和收益。基于我国特殊的人口结构状况,本文通过建立精算模型进行模拟,具体分析税惠政策的实施在未来50年内的成本和收益,并运用成本收益比和覆盖率两个变量进行评价。模拟结果发现：若税惠政策能够促进企业年金发展,使得覆盖率增加,成本收益比会逐渐在16%~17%的水平保持稳定。本文进一步研究了延迟退休政策和死亡率变化对税惠成本和收益的影响。     

Long‐run Effect of the Global Financial Crisis on Singapore's Tourism and the Economy

This study employs recent Singaporean tourism survey data, the updated Singaporean input–output tables and a computable general equilibrium model to gauge the long‐run effects of the 2008 global financial crisis and selected policy responses. The simulation results suggest that the global financial crisis has had mild negative long‐run effects on the overall development of Singapore's economy, and that the GST deduction policy ought to offset this negative effect.     

Flexible estimation of price response functions using retail scanner data

Kalyanam and Shively [1998. Estimating irregular pricing effects: a stochastic spline regression approach. Journal of Marketing Research 35 (1), 16–29] and van Heerde et al. [2001. Semiparametric analysis to estimate the deal effect curve. Journal of Marketing Research 38 (2), 197–215] have demonstrated the usefulness of nonparametric regression to estimate pricing effects flexibly. The empirical results of these two studies, however, also revealed that nonparametric regression may suffer from too much flexibility leading to nonmonotonic shapes for price effects. In this paper, we show how the problem of nonmonotonicity can be dealt with without losing the power of flexible estimation techniques. We propose a semiparametric approach based on Bayesian P-splines with monotonicity constraints imposed on own- and cross-price effects. In an empirical application, we illustrate that flexible estimation of own- and cross-price effects can improve the predictive validity of a sales response model substantially, even when price response curves were constrained to show a monotonic shape, as suggested by economic theory. We also discuss the consequences from an unconstrained estimation of price effects.     

Theory-Driven Choice Models

We explore issues in theory-driven choice modeling by focusing on partial-equilibrium models of dynamic structural demand with forward-looking decision-makers, full equilibrium models that integrate the supply side, integration of bounded rationality in dynamic structural models of choice and public policy implications of these models.     

基于IIEM的企业建模方法研究

在集成企业建模方法(IEM)的基础上,以一种基于可复用标准构件的改进的IEM建模方法(IIEM)来构建模型,该方法采用面向对象的建模技术和统一建模语言UML,通过构建可复用标准构件及扩充对象类和企业模型视图来实现企业模型,使企业模型具备了更好的适应性和主动性。最后通过一个实例说明了IIEM方法的可行性。