转变城市发展方式之低碳城市建设——基于德国经验借鉴

首先从产业能源体系、低碳交通网络及生态环境三方面梳理德国低碳城市建设实践,然后总结德国在低碳意识培养、战略目标制定、政策体系建设等方面值得借鉴的经验,最后从“公平-效率-质量”视角为我国低碳城市建设提出建设路径:加快创新驱动,提高建设效率;提供制度支持,注重建设公平;强调以人为本,提升建设质量。     

Study of emerging air taxi network operation using discrete-event systems simulation approach

This research focuses on understanding the air taxi operations to determine the number of air taxis required to fulfill the demand for urban air mobility in New York City (NYC). We leverage the Define, Measure, Analyze, Design, and Verify (DMADV) framework and integrate it with the systems simulation approach. Upon investigation, we find that all the parameters linearly impact the vehicle utilization, while other measures are robust, specifically with respect to the seating capacity. It is also recommended to operate initially with 70 air taxis in NYC to achieve a trade-off between customer wait time and vehicle utilization. The proposed approach can act as a recommender system for air taxi companies.     

The effects of group composition in a strategic environment: Evidence from a field experiment

Recent theoretical and empirical studies have explored the effect of group membership and identity on individual decision-making. This line of research highlights that economic models focusing on the individual as the sole entity in the decision-making environment potentially miss critical features. This study takes this literature in a new direction by overlaying a field experiment onto a setting where groups have arisen naturally. Our experimental laboratory is large open air markets, where we are able to examine the effects of group membership on seller׳s collusive behavior as measured by prices and surplus allocations. This permits us to explore strategic implications of group composition. Empirical results illustrate the importance of group composition on pricing decisions, and show that deviations from Nash equilibrium are crucially related to group membership.     

Utilizing urban form characteristics in urban logistics analysis: a case study in Lisbon,Portugal

Within the realm of urban logistics, Macário (2013) developed a hypothesis, denominated the Logistics Profile (LP) concept that suggests homogeneous groups of urban zones with respect to three dimensions, which could be used to analyze freight movement policy: (1) the social and built environment; (2) characteristics of the goods/products being moved; (3) characteristics of the deliveries at the receiver establishment. The concept was expected to ease the transferability of best practices in city logistics, by analyzing similarities and differences between zones. This research uses a quantitative methodology to apply the LP concept, and assess its potential, using the city of Lisbon as a case study. The analysis is focused on: (a) the extrapolation of freight trip generation per establishment and delivery characteristics from a sample of commercial establishments to the population within the case study, (b) proposing a methodology to test the LPs, (c) testing the existence of proposed LPs. Freight trips have been extrapolated using a Multiple Classification Analysis (MCA) model. Freight delivery characteristics were attributed to establishments from a sample-based probability distribution. LPs were tested using a two-step cluster analysis. Some LPs have been matched with clusters of case-study zones, subject to case study particularities. Profile overlap was not an issue and occurrences were expected. The testing showed that Logistic Profiles have the potential for being used as a departure point for urban freight planning and policy analysis.     

How Do Squatters Deal with the State? Legalization and Anomalous Institutionalization in Madrid

Radical and autonomous urban movements like the European squatters' movement tend to resist integration into the institutions of the state, although particular legal and political conditions in each country or city may significantly alter this tendency. In this article, I examine the controversial issue of ‘institutionalization’ among squatters, focusing on the few cases of legalized squats (social centres) in the city of Madrid. Negotiations with the state authorities and processes of legalization are the major forms of institutionalization involving squatters. However, an anomalous kind of institutionalization also emerges once squats, whether legalized or not, become consolidated and socially accepted. For squatting to have a successful impact, then, depends on both the type of autonomy achieved by squatters and the different outcomes of the processes of institutionalization. The case of Madrid provides empirical evidence that: (1) negotiations with state authorities were very frequent among squatters, but most were defensive; (2) the few cases of legalization were due to specific conditions such as the urban centrality of the squats, single‐issue identities, social network solidarity, favourable media coverage, formal organizations working as facilitators and the squatters' leadership of the process. Furthermore, legalized squats in Madrid preserved a high degree of autonomy, self‐management and ties to other radical social movements. In conclusion, both the legalized squats and the squatters' movement in Madrid as a whole, avoided ‘terminal institutionalization’ and, instead, gave shape to a ‘flexible’ one.     

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.     

Effects of land urbanization and land finance on carbon emissions: A panel data analysis for Chinese provinces

The rapid urbanization in China comes with several economic, social, and environmental issues, most of which are related to land use. This study contributes to research on the land–growth–environment nexus by investigating the effect of land urbanization and land finance on carbon emissions in China from 2004 to 2013 using the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model. Results show that land finance and land urbanization significantly affect carbon emissions. The rate of land urbanization contributes to the reduction of carbon emissions; however, it has less impact compared with other determinants. The effect of land finance and land urbanization on carbon emissions indicates that a local government’s willingness to lease land for revenue aggravates carbon emissions. Economic growth and industrial structure also influence carbon emissions. Furthermore, the land requisition system and rural land conversion market should be enhanced through the guidance provided by the 13th Five-Year Plan (2016–2020) to promote the diversification of land transfer, fully consider regional differences, and establish a distinct policy focus that can contribute to emission reduction and land use.     

城市化、政府财政支出、就业所有制结构与城乡收入差距

基于1985-2012年的数据,建立以城市化、政府财政支出、就业的所有制结构为内生变量的向量误差修正模型,并且用协整检验考察城市化水平、政府财政支出、就业的所有制结构的长期均衡与短期动态关系。实证分析发现:四者不仅存在长期的均衡关系,而且存在短期动态关系。具体而言,城市化、政府财政支出、就业的所有制结构在长期会扩大城乡收入差距,在短期则会缩小城乡收入差距。     

Urban Sensing by Crowdsourcing: Analysing Urban Trip behaviour in Zurich

The research on which this essay is based sought to provide a deeper understanding of live urban activities. The main idea was to obtain in‐depth trip information by integrating sensing technology with crowdsourcing‐based methods. Location and acceleration sensors embedded in smartphones can deliver useful trip information. Research had previously been conducted to find an accurate data analysis algorithm for high‐level data mining, an efficient sensing method for power saving. As a proof of concept, this essay presents a case study of Zurich that successfully implemented previous research achievements in the real environment. It established that urban travel behaviour can, in fact, be collected by sensors embedded in mobile devices, and that the data thus obtained can be used to measure the characteristics of trip behaviour in cities by means of an advanced classifying algorithm and analysis. The strength of this research is its pioneering role in clearing the ground for future urban data collection methods and planning strategies. Specifically, this study could provide answers to the following key questions: How can crowdsourcing be applied to the collection of urban transportation data? What kinds of information can be extracted from the crowdsourced mobile sensing platform? What kinds of knowledge, within the transportation domain, can be derived from the above?     

WHICH AGGLOMERATION EXTERNALITIES MATTER MOST AND WHY?

This paper revisits the ongoing discussion on the importance of agglomeration externalities – specifically specialization, diversity and competition effects – that may contribute to innovation, productivity and urban employment growth. Previous meta‐analyses suggested that the evidence on agglomeration externalities is strongly context‐specific. Expanding an earlier analysis of 31 articles, we seek to draw in this paper more robust conclusions by means of the statistical evidence for agglomeration externalities presented in 73 scientific articles, all building on the seminal work of Glaeser et al. (1992). Our results confirm that the heterogeneity among studies is huge and can only be partially accounted for by means of an ordered probit analysis. Additionally, some evidence of publication bias is found. We conclude that the conventional lines of inquiry in this literature may now have reached strongly diminishing returns. New lines of inquiry, using rich micro‐level data on firms and workers, dynamic general equilibrium models at the macro level, more attention for spatial and temporal variation in the impacts of agglomeration, and further investigations into the spatial scope of externalities are promising avenues for further research that can enhance our understanding of how agglomeration externalities continue to fuel our increasingly urbanized world.