城市科学20年的发展历程--祝贺中国城市科学研究会成立20周年

回顾北京市城市科学研究会的发展历程,分为多学科协同研究城市问题阶段;城市发展多学科综合研究阶段;城市发展综合研究向重点领域开展阶段.概括了北京城科会的主要学术成果.     

Ricardo on machinery: an analysis of Ricardo's examples

The examples that are reported in the famous chapter “On Machinery” added by Ricardo in the third edition of his Principles are reconstructed and analyzed. Two sets of assumptions that rationalize the examples presented by Ricardo are identified: a) the innovation concerns an agricultural commodity and does affect neither which land is marginal nor the technology applied on the marginal land; b) the innovation concerns a non-basic commodity. Ricardo was aware of these two facts and he seems to have used them respectively in the first and second of his examples.     

Integrating ecosystem services into conservation assessments: A review

A call has been made for conservation planners to include ecosystem services into their assessments of conservation priority areas. The need to develop an integrated approach to meeting different conservation objectives and a shift in focus towards human wellbeing are some of the motivations behind this call. There is currently no widely accepted approach to planning for ecosystem services. This study contributes towards the development of this approach through a review of conservation assessments and the extent to which they include ecosystem services. Of the 476 conservation assessments identified by a set of search terms on the Web of Science, 100 were randomly selected for this review. Of these only seven had included ecosystem services, while another 13 had referred to ecosystem services as a rationale for conservation without including them in the assessment. The majority of assessments were based on biodiversity pattern data while 19 used data on ecological processes. A total of 11 of these 19 assessments used processes, which could be linked to services. Ecosystem services have witnessed an increase in attention received in conservation assessments since the year 2000, however trends were not apparent beyond this date. In order to assess which types of ecosystem services and how they have been accounted for in conservation assessments, we extended our review to include an additional nine conservation assessments which included ecosystem services. The majority included cultural ecosystem services, followed by regulatory, provisioning and supporting services respectively. We conclude with an analysis of the constraints and opportunities for the integration of ecosystem services into conservation assessments and highlight the urgent need for an appropriate framework for planning for ecosystem services.     

Does accessibility to local public employment agencies matter? Answers from a French quasi-experiment

We question whether accessibility to local public employment agencies impacts exits from unemployment. We deal with the potential endogeneity of the residential location of jobseekers by using the unanticipated creation of a new agency in the French region of Lyon as a quasi-natural experiment. We use exhaustive and geo-located individual data on jobseekers and local public employment agencies. Contrary to past evidence based on aggregated data, we find no evidence that jobseekers with improved accessibility to the local public employment services experience an improvement of their probability of exiting unemployment. We however find evidence of transitory organizational effects. These findings strongly question the costly strategy of a fine distribution of local public employment agencies across the territory while suggesting that institutional issues are key.     

Exploring purchasing integration in product development

With increasing outsourcing and the growing importance of product innovation as a means for creating competitive advantage, the integration of purchasing and product development processes has become a key issue for many firms. Although, consequently, the integration of purchasing and suppliers in product development has attracted growing attention from practitioners and researchers, most research on the topic remains limited to the context of single development projects. The integration with long-term issues such as technological alignment between supplier and manufacturer is often neglected. This limited conception and the lack of a coherent definition of what purchasing integration in product involvement is form a major impediment to the advancement of knowledge in this field. Therefore, this article develops a framework encompassing various activities across different management levels, which embody the alignment and integration of purchasing and product development processes.     

Replicating portfolio approach to capital calculation

The replicating portfolio (RP) approach to the calculation of capital for life insurance portfolios is an industry standard. The RP is obtained from projecting the terminal loss of discounted asset–liability cash flows on a set of factors generated by a family of financial instruments that can be efficiently simulated. We provide the mathematical foundations and a novel dynamic and path-dependent RP approach for real-world and risk-neutral sampling. We show that our RP approach yields asymptotically consistent capital estimators if the chaotic representation property holds. We illustrate the tractability of the RP approach by three numerical examples.     

Taxation and parental time allocation under different assumptions on altruism

This paper examines the effects of labor income taxation on parental time allocation in an OLG model in which child care arrangements, that is the combination of parental and non-parental time, matter for human capital accumulation. We show that the sign of the impact of labor income taxation on parental time with children and on growth critically depends on the assumption on the altruistic motives behind the choice of devoting time to children.     

Decomposing the market,industry, and firm components of profitability: implications for forecasts of profitability

Academics and practitioners frequently highlight that overall market and industry performance is an important aspect of a firm’s profitability. However, few studies allow for the decomposition of a firm’s profitability into market, industry, and idiosyncratic components, and those that do often assume that the market and industry components are cross-sectional constants. In this study, we allow for variation in firm-specific sensitivities to market, industry, and idiosyncratic economic shocks, and then assess whether and when this decomposition results in improved forecasts of profitability. For the overall sample, we find significant improvements in terms of the magnitude of forecast errors and the frequency with which forecasts based on the decomposed values are superior versus forecasts using only total profitability. Across the sample as a whole, decomposing profitability in the forecasting process results in more accurate forecasts greater than two-thirds of the time (increasing to almost 80% within certain subsamples). Our results provide strong support for the role that firm-specific measures of market and industry profitability play in predicting a firm’s future performance, as well as highlighting settings where the decomposition provides the greatest benefit in terms of predicting future changes in profitability.     

Audit personnel salaries and audit quality

This study examines the relation between audit personnel salaries and office-level audit quality. We measure audit personnel salaries at the associate, senior, and manager ranks for Big 4 audit offices from 2004 to 2013, using unique individual-auditor-level data obtained from the U.S. Department of Labor. We find that offices that pay lower salaries have a higher percentage of clients that experience restatements. In related analyses, we also find lower levels of audit quality when audit employees are paid less, relative to other lines of service in accounting firms. Finally, we document positive and significant associations between salary and fees, suggesting that audit offices pass some of the cost of higher labor onto their clients. Overall, our findings provide important initial evidence on the role of audit salary and its relation to audit quality and audit fees.