Relationship between city size and firm productivity – A new interpretation using the Chinese experience

This paper contributes to the literature on the relationship between city size and firm productivity by focusing on agglomeration, selection (market competition), and sorting (presence of firms with diverse productivity) effects using Chinese firm-level data for 1998–2013. Contrary to the existing literature, our parametric regression estimates from nearly two million firms show that when the selection effect is controlled, productivity advantage in big cities is reversed. This outcome is explained through a quantile regression showing the existence of left-sided sorting (inefficient firms sort themselves to larger cities) in big cities which is not captured in existing empirical literature. We further find that (1) left-sided sorting is stronger in exporters than non-exporters; (2) is also generated mainly in enterprises with high asset-liability ratios; and (3) selection has a positive effect on firm productivity, suggesting that market competition is key in an explanation of the rapid growth of big cities in China.     

Selective disclosure and the role of Form 8-K in the post-Reg FD era

We investigate the impact of Form 8-K filings on cross-firm differences in analysts’ private or idiosyncratic information in the post-Reg FD era. Using firms’ connections to the investment community to identify the likelihood of selective disclosure, we document differences in analysts’ idiosyncratic information arising from selective disclosure before 8-K filings. While filings of 8-Ks pursuant to Reg FD attenuate the link between connections and analysts’ idiosyncratic information, they do so only after selective disclosures have already resulted in some analysts having better private information. In addition, the connections continue to facilitate private information search after the filings of non-Reg FD-specific 8-Ks.     

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.     

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?