对普适性生产函数模型的一些改进

普适性生产函数方法为使用横截面数据估计时,由于各地区生产函数的不同所导致的不可估算问题,提供了很好地解决办法,但其参数的估计需用差分模型,这将产生严重的缺陷.文章放宽其基本假设,得到更一般的可估计模型——异方差模型,经验证据亦表明,改进后的模型优于原有模型.     

基于时变参数的我国全要素生产率估计

本文应用时变参数状态空间模型,利用1953~2005年中国宏观经济数据,估计了样本区间内我国的全要素生产率(TFP),并与传统的索洛残差方法的计算结果进行了比较。分析表明:时变参数方法得到的TFP增长率计算结果由于不包含方程误差,比索洛残差方法的结果精确;TFP增长率的变化趋势,基本和GDP的增长趋势相同,只是有所滞后,滞后期一般为一年。     

Impacts of Low-Cost Land Certification on Investment and Productivity

New land reforms are again high on the policy agenda and low-cost, propoor reforms are being tested in poor countries. This article assesses the investment and productivity impacts of the recent low-cost land certification implemented in the Tigray region of Ethiopia, using a unique household and farm-plot-level panel data set, with data from before and up to eight years after the reform. Alternative econometric methods were used to test and control for endogeneity of certification and for unobserved household heterogeneity. Significant positive impacts were found, including effects on the maintenance of soil conservation structures, investment in trees, and land productivity.     

Assessing the welfare effects of congestion charges in a real world setting

The standard textbook analysis shows that drivers as a group lose from congestion charges. However, it omits taste heterogeneity, shorter travel times far out in the larger network arising from less blocking back of upstream links and the possibility for drivers to reschedule. Taking account of these factors, using a dynamic scheduling model with heterogeneous users we find that all three add significantly to the benefit of the Stockholm congestion charges and that drivers as a group benefit from these charges even without recycling of revenues. This paper also provides an update on the consumer benefits of the Stockholm charges.     

Choice modelling with search and sort data from an interactive choice experiment

We present a highly structured, online, interactive choice environment containing a large number of alternatives, a search tool that eliminates alternatives that fail specified criteria, and a sort tool. A conceptual framework is developed that links tool usage and preference heterogeneity, and tested in the context of long-haul flight choice. Individuals who sort on price are more price sensitive; individuals who search on certain attributes have a greater marginal (dis)utility for that attribute; and individuals who perform certain non-price searches have a lesser price disutility. The method shows promise as a means for providing a richer picture of preference heterogeneity.     

Tradable travel credits for congestion management with heterogeneous users

This paper carries on the recent work of Yang and Wang (2011) on tradable credit schemes by considering heterogeneous users with different value of time (VOT). Given a tradable credit scheme, the user equilibrium (UE) and market equilibrium (ME) conditions with heterogeneous users are formulated into a variational inequalities (VI) problem. Sufficient conditions for uniqueness of the aggregate UE link flows and then the ME credit price are established. Appropriate tradable credit schemes are developed to decentralize system optimal and Pareto-improving network flow patterns. Extension is made to the elastic demand case.     

Endogeneity in survey research

Endogeneity is a crucial problem in survey-based empirical research on marketing strategy (MS) and inter-organizational relationships (IORs); if not addressed, it can cause researchers to arrive at flawed conclusions and to offer poor advice to practitioners. Although the field is increasingly cognizant of endogeneity-related issues, many authors fail to properly address it, particularly in survey-based research. Emphasizing the role of essential heterogeneity, this article develops an overarching framework to help improve the understanding of endogeneity problems and how to tackle them when researchers use cross-sectional survey-based data. The authors provide explanations of and advice for how MS and IOR researchers can address six “painful” and sometimes hidden decisions: 1) Do you have an endogeneity problem? 2) What technique/estimator is appropriate? 3) What instrumental variables (IVs) should be chosen? 4) How should IVs be evaluated empirically? 5) How should the results be interpreted and evaluated? and 6) What results should you report? The authors provide a practical flowchart to guide researchers in their efforts to address endogeneity-related concerns.     

An evolutionary Cournot oligopoly model with imitators and perfect foresight best responders

We consider the competition among quantity setting players in a linear evolutionary environment. To set their outputs, players adopt, alternatively, the best response rule having perfect foresight or an imitative rule. Players are allowed to change their behavior through an evolutionary mechanism according to which the rule with better performance will attract more followers. The relevant stationary state of the model describes a scenario where players produce at the Cournot‐Nash level. Due to the presence of imitative behavior, we find that the number of players and implementation costs, needed to the best response exploitation, have an ambiguous role in determining the stability properties of the equilibrium and double stability thresholds can be observed. Differently, the role of the intensity of choice, representing the evolutionary propensity to switch to the most profitable rule, has a destabilizing role, in line with the common occurrence in evolutionary models. The global analysis of the model reveals that increasing values of the intensity of choice parameter determine increasing dynamic complexities for the internal attractor representing a population where both decision mechanisms coexist.     

Multinational activity of European firms and heterogeneity

This paper offers an empirical assessment of the multinational activity of European firms. It takes the predictions of models of firm heterogeneity and FDI activity as a reference to explore the characteristics of multinational firms from 30 European countries. We use a data set, based on ORBIS, which links information of parent–affiliate pairs of firms. Our results show that more productive firms have greater multinational activity in terms of both scope, the number of foreign markets where they invest, and scale, the volume of local sales by subsidiaries active in foreign markets. The estimation of gravity equations shows that country characteristics that encourage multinational activity successively induce the entry of less productive parent firms. We confirm this asymmetry for the GDPs of the home and host countries, distance, contiguity and other standard gravity equation variables.     

众包接包者参与意愿影响因素研究：基于不可观测异质性的接包者类别探索

众包接包者参与意愿的影响因素包括参与动机、发包者因素和平台因素,但不同研究在因素影响强度上尚未达成共识。文章在验证众包参与意愿影响因素模型的基础上,结合有限混合偏最小二乘法和多群组分析方法,解析了不可观测异质性的调节作用,并探索性地识别了接包者细分群体。结果显示,对总体样本而言,外在动机、任务设计、平台环境和网站体验显著影响众包参与意愿;不可观测异质性显著调节参与动机与众包参与意愿的关系,对发包者因素及平台环境与众包参与意愿间关系的调节作用得到部分支持;三个细分群体方案是解释不可观测异质性的最优选择,包括：外在动机驱动型、外因驱动型及内在动机驱动型,不同类型接包者对因素影响强度程度的认知不同。研究结果为组织者清晰地认识接包者和制定更具效度的激励策略提供了启示。