A general endogenous grid method for multi-dimensional models with non-convexities and constraints

The endogenous grid method (EGM) significantly speeds up the solution of stochastic dynamic programming problems by simplifying or completely eliminating root-finding. We propose a general and parsimonious EGM extended to handle (1) multiple continuous states and choices, (2) multiple occasionally binding constraints, and (3) non-convexities such as discrete choices. Our method enjoys the speed gains of the original one-dimensional EGM, while avoiding expensive interpolation on multi-dimensional irregular endogenous grids. We explicitly define a broad class of models for which our solution method is applicable, and illustrate its speed and accuracy using a consumption–saving model with both liquid assets and illiquid pension assets and a discrete retirement choice.     

民营企业的可持续发展及风险防范

民营企业是我国经济持续发展的重要力量,针对民营企业的发展过程、现状及存在的风险,用企业演化理论阐述我国民营企业的能力演化及特点,以利于为民营经济在可持续发展过程中如何防范风险提供方略。     

Bayesian forecasting and portfolio decisions using dynamic dependent sparse factor models

We extend the recently introduced latent threshold dynamic models to include dependencies among the dynamic latent factors which underlie multivariate volatility. With an ability to induce time-varying sparsity in factor loadings, these models now also allow time-varying correlations among factors, which may be exploited in order to improve volatility forecasts. We couple multi-period, out-of-sample forecasting with portfolio analysis using standard and novel benchmark neutral portfolios. Detailed studies of stock index and FX time series include: multi-period, out-of-sample forecasting, statistical model comparisons, and portfolio performance testing using raw returns, risk-adjusted returns and portfolio volatility. We find uniform improvements on all measures relative to standard dynamic factor models. This is due to the parsimony of latent threshold models and their ability to exploit between-factor correlations so as to improve the characterization and prediction of volatility. These advances will be of interest to financial analysts, investors and practitioners, as well as to modeling researchers.     

CRM动态能力维度对顾客资产的作用机制研究

顾客资产是企业的一项关键资产,对其进行有效的评估及管理将有利于企业绩效的提高,因此,建立和维持CRM动态能力将使企业具有持续的竞争优势.文章从上述这一个新的视角构建了顾客资产的效果机制模型.同时,分别从市场导向、社会网络能力、资源重构三个维度的重要性验证了对营销效果和顾客资产的影响存在差异性,并发现了营销情报与顾客响应的内在统一性.     

2002—2017年厦门市景观格局与热环境的时空耦合关系

基于2002、2007、2012、2017年4期Landsat遥感影像,应用景观生态学和统计分析相结合的方法,探讨了厦门景观格局对热环境的影响作用及其变化规律。结果表明,2002—2017年,厦门市相对地表温度(Relative Land Surface Temperature,RLST)呈上升趋势,城区的热岛效应逐步凸显;RLST较高的区域多为耕地、建设用地,RLST较低的区域多为绿地、水体;在类型层面,绿地的景观类型比例、最大斑块指数、聚集度指数、平均斑块面积、形状指数与相对地表温度呈负相关,斑块密度、边缘密度与RLST呈正相关。耕地、建设用地的景观指数与RLST均呈正相关;在景观层面,景观分割指数、形状指数、斑块密度、边缘密度、香浓均匀度指数与RLST呈正相关;景观优势度大、聚集度高的景观类型,如耕地、绿地、建设用地对RLST影响显著。随着城区的扩张与耕地的减少,建设用地景观格局对RLST的影响逐渐加强,而耕地景观格局对RLST的影响不断减弱;景观层面的景观格局对RLST的影响作用与不同景观类型总体的结构组分及空间构型有关。随着景观结构趋于复杂,景观层面的景观格局对RLST的影响逐渐增强。     

基于内容分析法的科技成果转化政策演进趋势分析

科技成果转化政策是强化科技与经济联系,完善创新体系的重要手段,是推动创新驱动、实现高质量发展的关键。论文选取1996—2017年中国中央政府及各部委所发布的85篇与科技成果转化相关的政策文本,采用内容分析法对其演进趋势及内在规律分析,得出政策制定部门参与水平上升、政策工具搭配组合日益多元、重视提升政策客体转化积极性的结论,并对未来政策发展方向提供思路。     

How an international ambidexterity strategy can address the paradox perspective on corporate sustainability: Evidence from Chinese emerging market multinationals

Corporate sustainability (CS) is receiving considerable attention from emerging market multinational enterprises (EMNEs), playing an important role in the globalized market. However, theoretical and empirical knowledge about how EMNEs address CS is still scant, and the relationship between internationalization and CS has not been widely explored. This study aims to fill this gap, evaluating the relationship between an international ambidexterity strategy and CS in EMNEs, which highlighted the paradox perspective. Then we develop three hypotheses in which we argue how the dynamic capabilities underpinning international ambidexterity could be considered a driver of CS in EMNEs. We test the developed hypotheses against data from 300 Chinese EMNEs obtained by a survey. Our results contribute to shape ambidextrous international strategies and to consider CS as a springboard for the strategic intent to systematically and recursively outperform global competition. Testing a measurement scale of international ambidexterity, we suggest structural ambidexterity as a strategic option of internationalization that allows the achievement of economic, social, and environmental sustainability objectives.     

京津冀城市大气环境竞争力评价

从大气环境与城市竞争力的关联性入手,将大气环境风险、现状和治理纳入评价指标体系,基于组合权重的大气环境竞争力评价模型,对2013-2017年京津冀13个城市的大气环境竞争力水平进行了测评,并结合空间自相关分析和障碍度模型揭示了其空间效应及障碍因素。结果显示:京津冀城市大气环境竞争力存在明显的空间差异,呈北部高、南部低、局部跳跃格局,城市差距逐渐缩小;京津冀城市大气环境竞争力呈显著的空间集聚效应且存在正向相关性,空间分布格局相对稳定。     

Behavioral equilibrium and evolutionary dynamics in asset markets

This paper analyzes a dynamic stochastic equilibrium model of an asset market based on behavioral and evolutionary principles. The core of the model is a non-traditional game-theoretic framework combining elements of stochastic dynamic games and evolutionary game theory. Its key characteristic feature is that it relies only on objectively observable market data and does not use hidden individual agents’ characteristics (such as their utilities and beliefs). A central goal of the study is to identify an investment strategy that allows an investor to survive in the market selection process, i.e., to keep with probability one a strictly positive, bounded away from zero share of market wealth over an infinite time horizon, irrespective of the strategies used by the other players. The main results show that under very general assumptions, such a strategy exists, is asymptotically unique and easily computable.     

A simple characterisation for sustained growth

This article considers an inter-temporal optimisation problem in a general form and gives conditions ensuring the convergence to infinity of the economy. These conditions can be easily verified and applied for a large class of problems in the literature. Some applications for different economies are given as illustrative examples.