Factor state–space models for high-dimensional realized covariance matrices of asset returns

We propose a dynamic factor state–space model for high-dimensional covariance matrices of asset returns. It makes use of observed risk factors and assumes that the latent integrated joint covariance matrix of the assets and the factors is observed through their realized covariance matrix with a Wishart measurement density. For the latent integrated covariance matrix of the assets we impose a strict factor structure allowing for dynamic variation in the covariance matrices of the factors and the residual components as well as in the factor loadings. This factor structure translates into a factorization of the Wishart measurement density which facilitates statistical inference based on simple Bayesian MCMC procedures making the approach scalable w.r.t. the number of assets. An empirical application to realized covariance matrices for 60 NYSE traded stocks using the Fama–French factors and sector-specific factors represented by Exchange Traded Funds (ETFs) shows that the model performs very well in- and out of sample.     

协调发展战略下地方政府合作的动力机制探析--以深汕特别合作区为例

党的十九大报告首次提出区域协调发展战略,要求各地充分发挥比较优势,加强政府间合作,着力解决区域发展不平衡不充分的问题。深汕合作区正是实施这一战略的典型代表。其中,政府的战略政策导向、经济全球化、区域一体化和非政府组织的发展是合作区得以形成的主要外部动力;区域协调发展、产业结构调整、官员升迁诉求是内部动力。但是,在合作区发展的过程中也存在一定的阻力。如地方保护主义的抬头、利益博弈、市场运作的行政化。因此,为促进地方政府间良性合作,应不断强化合作的正向激励,降低合作的阻力,保证区域府际合作的长久性。     

Economics of household food waste

Food waste has drawn increasing public attention, and the high levels of estimated waste are largely considered to be a failure of our current food system. Recently, economists have begun to weigh in, showing food waste can emerge as the result of a complex equilibrium affected by consumers’ preferences for convenience; expectations about future food prices and availability; food safety concerns; producers’ costs of holding inventory, transportation, and storage; government regulation; and technology. If food waste is a form of inefficiency, there are either strong economic motivations to reduce waste, or unmeasured costs or preferences affecting waste decisions. If consumers have behavioral biases, suffer from information asymmetries, or do not pay the full cost of their waste, there may be a role for government intervention to reduce waste, but most empirical models in the literature have not articulated or quantified the extent of the deadweight loss from the market failures in relation to food waste. In some cases, waste reduction efforts could harm producers if overall demand for food is reduced or harm consumers if overconsumption is encouraged, quality or safety degrades, or supply disruptions occur. Technological innovations, which lower the cost of storage or extend shelf life have the potential to improve both consumer and producer welfare.     

基于DEA-SBM模型的中国地板上市企业环境效率研究

考虑非期望产出,基于企业层面,根据2011-2016年数据,采用DEA-SBM模型与DEA-CCR模型对中国12家地板上市公司的环境效率与经济效率进行测算与比较。结果表明:2016年环境效率和经济效率测算结果显示不同地板上市企业运行效率存在差别;与经济效率相比,一些企业如北新建材、扬子地板,环境效率保持不变,一些企业如宜华生活、吉林森工和丰林集团,环境效率得到提升;还有一些企业如兔宝宝、升达林业和大自然家居等,环境效率则出现下降。考虑了非期望产出,中国地板上市企业整体环境效率均值低于经济效率均值,总体处于0.79~0.84之间。提出了政府应加强监管力度,地板上市企业应提高技术改进能力,建立完善社会责任信息披露机制的建议。     

农户参与乡村旅游扶贫的影响因素研究——以福建省赤溪村为例

以福建省赤溪村农户为调研对象,运用相关性检验和二元Logistic回归模型对影响农户参与乡村旅游扶贫的因素进行研究。研究发现:农户参与乡村旅游扶贫的比例较高,但是旅游经营的项目单一;农户的学历、劳动力数量、地理位置、参与乡村旅游扶贫培训的次数对农户参与乡村旅游有显著地正向影响作用;农户生计资本和对旅游发展的感知中的权力关系、可借款能力、家庭年收入、了解乡村旅游扶贫政策、有资源用于发展乡村旅游也是影响农户参与的主要因素。在此基础上,提出了加大扶贫政策宣传力度,提高旅游扶贫政策利用程度完善旅游相关基础设施,扩大农户扶贫资金来源渠道,完善扶贫资金体系,完善旅游供给侧创新旅游经营模式,实行多项扶持的针对性建议。     

Islamic and conventional portfolios optimization under investor sentiment states: Bayesian vs Markowitz portfolio analysis

This paper investigates the portfolio optimization under investor’s sentiment states of Hidden Markov model and over a different time horizon during the period 2004–2016. To compare the efficient portfolios of the Islamic and the conventional stock indexes, we have employed two approaches: the Bayesian and Markowitz mean-variance. Our findings reveal that the Bayesian efficient frontier of Islamic and conventional stock portfolios is affected by the investor’s sentiment state and the time horizon. Our findings also indicate that the investor’s sentiment regimes change the Islamic and the conventional optimal diversified portfolios.Moreover, the results show that the potential diversification benefits seem to be more important when using the Bayesian approach than when applying the Markowitz approach. This finding is valid for the bearish, depressed, bullish and calm states in Islamic stock markets. However, the diversification of potential portfolios is significant only for the bullish and the bubble states in the conventional financial markets.The findings of the study provided additional evidence for investors to exploit googling investor sentiment states to evaluate the portfolio performance and make an optimal portfolio allocation.     

Modelling distribution of aggregate expenditure on tourism

The aim of this article is to obtain a statistical distribution that describes the aggregate expenditure of tourists related to their length of stay at a given location. This distribution enables us to estimate two parameters simultaneously; one controls the length of stay and the other, the expense incurred. We propose two distribution models, for which closed-form expressions are obtained. Covariates are introduced in order to study the factors that affect the aggregate expenditure. The results obtained indicate that the models achieve a reasonably good fit, with and without covariates.     

Analysis of the effect of charging infrastructure design on electric taxi driving profiles: A case study approach on the example of Singapore

Replacing conventional vehicle taxis with electric vehicles would be an efficient measure to reduce greenhouse gas emissions. Due to the limited range and long charging times of current battery electric vehicles, it is of utmost importance to provide sufficient charging facilities. This article analyses the impact of the placement and charging power of charging stations on potential mileage and revenue of electric taxis on the example of Singapore. Therefore, we developed an agent-based electric taxi simulation model to investigate electric taxis’ driving profiles with respect to different vehicle types and charging infrastructure designs. This model is also capable of simulating conventional taxi driving profiles. The validation of these simulation results with real taxi data showed that the model is reproducing taxi driving profiles with high accuracy in great detail. We found out that electric taxis could reach the same mileage and revenue as conventional taxis if charging with a power of 160?kW is possible. Furthermore, we discovered that waiting times for available charging stations have a stronger effect on revenue than the length of detours to reach charging stations. Based on these findings, we concluded that it is more important to reduce waiting times by placing sufficient numbers of charging stations at each location before expanding the charging network by installing small numbers of charging stations at many locations.     

The effect of diplomatic representation on trade: A panel data analysis

This study addresses current gaps in the empirical literature regarding the effect of diplomatic representation on trade using a panel data set for 100 countries with 5‐year interval data from 1985 to 2005 and four‐digit level industry data. The results indicate that the effect of diplomatic representation on exports in differentiated goods is positive and significant and larger than on exports in homogeneous goods on average, but not statistically different from it. Furthermore, diplomatic representation only increases trade along the extensive margin and not along the intensive margin. The results indicate that diplomatic representation is effective in performing its function as a network search intermediary and that it is a useful policy tool to alleviate market failure.     

From disruptively digital to proudly analog: A holistic typology of digital transformation strategies

Recently booming academic interest in digital transformation aims to provide continuous support to managers in dealing with this important issue. However, as with all new fields, the scholarly literature is characterized by increased variability and diversity of topics covered, constructs used, and the relationships between them, resulting in an unclear and blurry understanding of the whole of digital transformation. Our article closes this gap by identifying distinctive digital transformation strategies in terms of two critical dimensions: usage of digital technologies and readiness of a business model for digital operation. The result is a typology of four generic digital transformation strategies that essentially differ in the primary motivation and target of transformation, leadership style, importance of skills like creativity and entrepreneurial spirit among employees, risks and challenges faced in the process, consequences of potential failure, and available tactics for improvement. By providing heuristics and a systematic basis for comparison of different strategies, it is our belief that the proposed framework will be useful to researchers and managers responsible for and interested in digital transformation.