中国宏观经济总量的实时预报与短期预测——基于混频数据预测模型的实证研究

季度GDP的走势与波动不仅会影响政府的财政收支、企业的盈利和财务状况,甚至还会影响家庭和个人的收入与支出,是宏观经济总量预报、预测与分析的重中之重。传统的宏观经济总量预测模型是基于同频数据进行的,高频和超高频数据必需处理为低频数据,这不仅忽略了高频数据信息的变化,还影响了模型预报和预测的及时性,降低了模型的预测精度。本文将混合数据抽样模型(MIDAS)用于中国季度GDP的预报和预测,实证研究表明,出口是造成我国金融危机时期经济增长减速的主要因素,MIDAS模型在中国宏观经济总量的短期预测方面具有精确性的比较优势,在实时预报方面具有显著的可行性和时效性。     

Regional airport choice: Consumer behaviour and policy implications

The analysis of origin airports in multi-airport regions has a well established tradition in transportation and regional economics. The main goal of the paper is to estimate the importance of the different attributes that determine origin airport choice. In our case we adopt a stated preference approach to study this problem and evaluate the effects of possible policy interventions. We also perform a detailed segmentation of the sample studied according to the socio-economic variables that prove statistically relevant when interacted with the attributes used to characterise airport choice. Moreover, in order to test for the presence of heterogeneity in agents’ preferences we estimate several mixed logit models with different specifications, including heteroscedasticity and error component. With respect to previous studies we develop and extend the traditional SP approach by also analysing the role and relevance of attribute cut-offs in this research field. The policy simulations produced are based on the estimation of airport-specific attributes. The study concentrates on a multi-airport region in central Italy where four competing airports are located.     

Forecasting value at risk and expected shortfall with mixed data sampling

I propose applying the Mixed Data Sampling (MIDAS) framework to forecast Value at Risk (VaR) and Expected shortfall (ES). The new methods exploit the serial dependence on short-horizon returns to directly forecast the tail dynamics of the desired horizon. I perform a comprehensive comparison of out-of-sample VaR and ES forecasts with established models for a wide range of financial assets and backtests. The MIDAS-based models significantly outperform traditional GARCH-based forecasts and alternative conditional quantile specifications, especially in terms of multi-day forecast horizons. My analysis advocates models that feature asymmetric conditional quantiles and the use of the Asymmetric Laplace density to jointly estimate VaR and ES.     

赋予科研人员职务科技成果所有权的法律释义及实现路径

赋予科研人员职务科技成果所有权,是从权属规则设计上解决科技成果转化难的国家政策。但现行《合同法》、《科技进步法》、《科技成果转化法》等法律相关规定对政策试点形成制约,弱化了政策实施力度。从法律视角廓清科技成果定义及类型,界定科研人员性质及范围,探寻科技成果所有权改革的政策目的,并对政策执行面临的法律障碍进行分析,提出以意定优先为原则修订相关法律,以有利于科研人员的基准进行立法解释,并通过单位与科研人员事前协议、约定职务科技成果归属等路径,将职务科技成果所有权依法赋予科研人员,从而解决法律规定与政策执行冲突,确保政策实施的法律正当性。     

第三方物流的监督博弈研究

由于物流外包中物流需求方与物流服务商之间的签约后的信息不对称,带来了第三方物流中的道德风险。物流需求方通过对第三方物流服务商的监督激励能够有效地减少服务商的机会主义行为,提高服务商的服务水平,克服第三方物流应用中的负面效应。本文基于物流外包中第三方物流的违规动机和外包的风险,运用非合作博弈论的理论和方法,构建了第三方物流的监督博弈模型,并应用混合纳什均衡模型对第三方物流的监督问题进行了定量分析,详细分析了物流需求方和服务商的决策行为,求出了混合战略纳什均衡点,得出了制约博弈双方决策行为的关键因素,并提出了对第三方物流企业进行有效监督的若干建议,为物流需求方提供了有效监督决策的理论依据和实践参考。     

How effective are heuristic solutions for electricity planning in developing countries

Heuristic algorithms have been widely used to provide computationally feasible means of exploring the cost effective balance between grid versus off grid sources for universal electrification in developing countries. By definition in such algorithms however, global optimality is not guaranteed. We present a computationally intensive but globally optimal mixed integer non-linear programming (MINLP) model for electricity planning and use it in a Monte Carlo simulation procedure to test the relative performance of a widely used heuristic algorithm due to [28]. We show that the overall difference in cost is typically small suggesting that the heuristic algorithm is generally cost effective in many situations. However we find that the relative performance of the heuristic algorithm deteriorates with increasing degree of spatial dispersion of unelectrified settlements, as well as increasing spatial remoteness of the settlements from the grid network, suggesting that the effectiveness of the heuristic algorithm is context specific. Further, we find that allocation of off grid sources in the heuristic algorithm solution is often significantly greater than in the MINLP model suggesting that heuristic methods can overstate the role of off-grid solutions in certain situations.     

A quintessential immigrant niche? The non-case of immigrants in the Dutch construction industry

Students of immigrant entrepreneurship show a distinct preference for ethnic concentrations. They focus on small entrepreneurship in sectors with large concentrations of immigrant businesses or on ethnic commercial precincts. This preference stems from practical and theoretical considerations. It seems that the study of such concentrations, or niches, is essential to the theoretical understanding of the structural determinants of small entrepreneurship and the processes of economic incorporation of immigrants. This paper challenges this orthodoxy. It argues that it is important to assess the factors and processes that positively and negatively affect the formation of niches. This argument is corroborated by an analysis of the construction industry in the Netherlands. According to Waldinger (1995: 577), ‘construction represents the quintessential ethnic niche’, but immigrants in the Netherlands did not carve out a niche. This exceptional situation can be attributed to a sector-specific configuration of social, economic and institutional processes.     

Optimal dividend policy and growth option

We analyse the interaction between the dividend policy and the decision on investment in a growth opportunity of a liquidity constrained firm. This leads us to study a mixed singular control/optimal stopping problem for a diffusion that we solve quasi-explicitly by establishing a connection with an optimal stopping problem. We characterize situations where it is optimal to postpone the distribution of dividends in order to invest at a subsequent date in the growth opportunity. We show that uncertainty and liquidity shocks have an ambiguous effect on the investment decision.      

A DC programming heuristic applied to the logistics network design problem

This paper proposes a new heuristic method for the logistics network design and planning problem based on linear relaxation and DC (difference of convex functions) programming. We consider a multi-period, multi-echelon, multi-commodity and multi-product problem defined as a large scale mixed integer linear programming (MILP) model. The method is experimented on data sets of various size. The numerical results validate the efficiency of the heuristic for instances with up to several dozens facilities, 18 products and 270 retailers.     

Optimization of postal express line network under mixed driving pattern of trucks

Details about the movement of trucks on postal express lines are investigated to improve the performances of mail distribution. A mixed driving pattern of trucks is introduced to minimize the transportation cost of a postal express line network with a service level requirement. We formulate this problem as a mixed p meeting depots location with shipment scheduling problem and build a MINLP model. A two-level tabu search procedure based on shipment grouping method is developed. Through a series of computational experiments and sensitivity analysis on different instances, some managerial insights of the network under mixed driving pattern are revealed.