逆向选择视角下电子商务市场与传统市场间关系研究

电子商务的出现和快速成长反映出它对信息环境具有支配性的优点,这本身就意味着电子商务市场可能成为传统市场的替代。然而,逆向选择问题明显限制了这种替代效应程度。文章基于经典逆向选择模型,通过所构造的双市场(传统市场与电子商务市场)逆向选择模型,证明伴随着质量不确定性而诱发的逆向选择问题,在电子市场和传统市场之间会产生市场的不均衡,从而导致渠道冲突。文章试图揭示传统市场和电子商务市场并存的学理根源,得出两市场间市场细分的条件,对两市场间的渠道冲突提出新的解释,并据此提出了逆向选择下企业营销的策略建议。     

抽样调查中无回答误差的分析与调整

分析无回答误差产生的原因和影响,在抽样调查的过程中,结合市场调查的次序和方式采取无回答误差的预防措施。对已经产生无回答的数据,用样本替代法和加权调整法对缺失数据进行调整,这两种方法都提高了调查数据的可靠性和准确性,有效降低无回答率。     

On structural inelasticity of modal substitution in freight transport

At the European level there is an increasing focus on how freight transport can be moved from trucks on roads to more environmentally friendly modes such as rail and ship. A large proportion of the transport services between OD pairs, however, cannot be substituted since there is only one alternative available. The paper investigates the magnitude of this “structural inelasticity” of modal substitution in freight transport due to a sparser layout of rail and ship-based freight networks compared to road. In the analysis we use a recent Scandinavian freight demand model covering more than 800 zones. We find that the structural inelasticity is very significant - in particular for transportation over less than 500 km. Moreover, the inelasticity varies greatly with commodity groups and between OD pairs, and it depends strongly on the port and rail infrastructure. The results suggest that pure charging instruments (road pricing for trucks) in many regions will have limited mode substitution impacts. However, if combined with structural changes in terms of improved infrastructure for rail and ship, impacts may be greater.     

Precautionary Saving and Endogenous Labor Supply with and without Intertemporal Expected Utility

We analyze precautionary saving behavior in a framework with labor and nonlabor income risks, an endogenous supply of labor, and a representation of preferences that disentangles attitudes toward risk, attitudes toward intertemporal substitution, and ordinal preferences for consumption and leisure. This preference structure allows us to disentangle and to describe in an intuitive way the different forces that determine precautionary saving “in the small” and “in the large.”     

Understanding the retirement-consumption puzzle through the lens of food consumption-fuzzy regression-discontinuity evidence from urban China

This paper provides an understanding of the widely-documented retirement-consumption puzzle from the perspective of food consumption. Exploiting the mandatory retirement age cut-off for public-sector male employees in urban China to obtain a source of exogenous variation in their retirement status, this paper identifies the causal impacts of retirement on four major aspects of their food consumption: food expenditure, time spent in food acquisition, the quantity and quality of food consumed. Based on data from the China Health and Nutrition Survey, our fuzzy regression-discontinuity analysis finds that, consistent with the retirement-consumption puzzle, retirement reduces elderly males’ total food expenditure by 49–55%. However, retirement barely changes the quantity of food they consume (measured by total calorie intakes). Further analysis suggests that elderly males substitute time for money in food acquisition upon retirement, which helps to reconcile the differential impacts of retirement on food expenditure and food consumption. Finally, retirement greatly changes elderly males’ diet structure. They consume significantly less food with animal origins (and thus less fat and protein) and more grains (and thus more carbohydrate) upon retirement, which undermines their diet balance by the standards provided by the Chinese Nutrition Association.     

产业融合产生过程的模型研究

根据自组织理论,产业融合产生的过程以融合型产品出现为标志,分为从无到有、从出现到实现两个阶段。文章结合单个产业发展模型,构建了产业融合产生过程的数学模型,并在此基础上运用数值模拟统计软件对产业融合产生过程的模型进行了验证。文章认为,产业融合模型的合理性及融合型产品的替代效应在产业融合的实现过程中起着关键作用。     

Rooted in Place: Understanding Camper Substitution Preferences

This study examines recreationists using primitive roadside campsites on Forest Preserve lands in the Adirondack Park. The primary objective of this study was to explore psychological factors (experience use history, enduring involvement, place bonding) that contribute to visitors’ substitution preferences and their willingness to make a resource substitution for roadside camping in the Adirondack Park. Two discriminant function analyses indicate that experience use history variables and the rootedness dimension of place bonding can significantly discriminate between substitution preference groups and willingness to substitute for roadside camping. Enduring involvement in the activity of camping, however, was not a significant predictor of substitution variables.     

基本养老金替代率合意水平研究——以上海市城镇居民为例

社会保障制度是人类社会文明进步的标志,社会养老保险是其中一项重要制度,其建立对社会的平稳发展有重要影响.在人口老龄化日益深化的时期,及时有效地对社会养老保险制度进行改革势在必行.在改革过程中,对基本养老金替代率的合意水平进行研究具有深远意义.以上海市城镇居民为例,建立基本养老金收支平衡模型,将计算出的合意供给替代率与现实需求替代率进行对比.结果对比发现,需求与供给难以匹配,对不匹配的基本原因进行分析,并在此基础上提出相应对策.     

FDI对国际贸易的互补与替代效应:基于我国主要贸易伙伴的平行数据实证研究

将我国主要贸易伙伴按贸易方式、商品结构及地理距离分成三组,分别使用平行数据的截面SUR方法对各组与我国出口额、进口额和上年FDI、截至上年的累积FDI及当年GDP总和进行回归分析,发现短期内,第一组FDI对国际贸易起互补效应,第二组起替代效应,第三组效应不明显.在长期,三组数据的累积FDI对国际贸易均有显著促进效应.     

Technological Progress and Youth Employment in South Korea

ABSTRACT

This paper analyzes the extent to which technology progress and youth employment are related. In doing so, we divide workers into two groups – young workers and old (prime-aged) workers - and then estimate the elasticity of substitution between (physical) capital and workers à la Jaimovich et al. (2013. “The Demand for Youth: Explaining Age Differences in the Volatility of Hours.” American Economic Review 103 (7): 3022–3044) by using the Korean labour market data between 2000 and 2014. Our findings indicate that the elasticity of substitution is greater (or at least not smaller) for young workers than for old workers.