Does Gibrat's Law hold among young,small firms?

According to Gibrat's Law of Proportionate Effect, the growth rate of a given firm is independent of its size at the beginning of the examined period. Aimed at extending this line of investigation, the present paper uses quantile regression techniques to test whether Gibrat's Law holds for new entrants in a given industry: that is for new small firms in the early stage of their life cycle. The main finding is that for some selected industries in Italian manufacturing Gibrat's Law fails to hold in the years immediately following start-up, when smaller firms have to rush in order to achieve a size large enough to enhance their likelihood of survival. Conversely, in subsequent years the patterns of growth of new smaller firms do not differ significantly from those of larger entrants, and the Law therefore cannot be rejected.JEL Classification: L11, L60Previous versions of this paper were presented at the 27th Annual EARIE Conference (Lausanne, 7-10 September 2000) and at seminars held between 2000 and 2003 at the Economics Department of Harvard University, the Catholic University of Milan, the University of Ferrara, the University of Bologna, the Bank of Italy, and Athens University of Economics & Business. We would like to thank Carlo Bianchi, Giuseppe Colangelo, Giovanni Dosi, Steven Klepper (Editor), Stephen Martin, Ariel Pakes, Aman Ullah and, in particular, Helen Louri and two anonymous referees for their valuable comments on earlier drafts. Financial support from MIUR (Year 2000; protocol #MM13038538_001; project leader: E. Santarelli) is gratefully acknowledged.Correspondence to: E. Santarelly     

Technological change and industry structure: A case study of the petroleum industry

This paper is a case study of the impact of an exogenous improvement of a process technology on the structure of the petroleum industry. The paper examines the role of three-dimensional seismology in bringing about the 1990s oil industry consolidation. This proposition is examined in the context of evolutionary economics and in a non-cooperative game theory, concluding with a reference to Steindl's theory of industry dynamics. The significance of this contribution lies chiefly in highlighting the fact that exogenous technological change can, under appropriate conditions, play a significant role in industry dynamics. This reference to the exogenous change in technology is a departure from the traditional consideration of endogenity of industry structure in relation to technological development and, therefore, a novelty. Secondly, the documentation of 3D seismology as a significant process technology of the petroleum industry is significant.     

干旱区土地利用结构调整的SD模型研究：以新疆吐鲁番市为例

土地利用结构的调整是我国目前土地利用总体规划的两大核心内容之一。我国干旱地区生态环境十分脆弱、稳定性差。土地沙漠化、盐碱化、草场退化等现象十分严重,本文以新疆吐鲁番市为例．分析了该市土地利用现状和存在的问题．运用系统动力学模型．建立了土地利用结构调整的动态模型,充当地制订中长期土地利用总体规划提供科学依据。     

Accounting for the ecosystem services of migratory species: Quantifying migration support and spatial subsidies

Migratory species support ecosystem process and function in multiple areas, establishing ecological linkages between their different habitats. As they travel, migratory species also provide ecosystem services to people in many different locations. Previous research suggests there may be spatial mismatches between locations where humans use services and the ecosystems that produce them. This occurs with migratory species, between the areas that most support the species' population viability - and hence their long-term ability to provide services - and the locations where species provide the most ecosystem services. This paper presents a conceptual framework for estimating how much a particular location supports the provision of ecosystem services in other locations, and for estimating the extent to which local benefits are dependent upon other locations. We also describe a method for estimating the net payment, or subsidy, owed by or to a location that balances benefits received and support provided by locations throughout the migratory range of multiple species. The ability to quantify these spatial subsidies could provide a foundation for the establishment of markets that incentivize cross-jurisdictional cooperative management of migratory species. It could also provide a mechanism for resolving conflicts over the sustainable and equitable allocation of exploited migratory species.     

私家车从事网约车运营保险争议分析及应对

私家车辆从事网约车载客行为而引起了大量纠纷,结合法院判决和其中事实判断涉及诸多争议.私家车"变脸"网约车进行载客不一定都使得危险显著增加,有些只是兼职网约车司机,风险程度不符合危险显著增加的三个特性,重要性、持续性和未曾估价性.网约车载客与交通事故发生不是必然的因果关系,只是路线不确定和行驶频率增加造成事故风险增加,让...     

The Learning Tourism Destination: The potential of a learning organisation approach for improving the sustainability of tourism destinations

Globalisation, increasing complexity, and the need to address triple-bottom line sustainability have seen the proliferation of Learning Organisations (LO) who, by definition, have the capacity to anticipate environmental changes and economic opportunities and adapt accordingly. Such organisations use system dynamics modelling (SDM) for both strategic planning and the promotion of organisational learning. Although SDM has been applied in the context of tourism destination management for predictive reasons, the current literature does not analyse or recognise how this could be used as a foundation for an LO. This study introduces the concept of the Learning Tourism Destinations (LTD) and discusses, on the basis of a review of six case studies, the potential of SDM as a tool for the implementation and enhancement of collective learning processes. The results reveal that SDM is capable of promoting communication between stakeholders and stimulating organisational learning. It is suggested that the LTD approach be further utilised and explored.     

The impacts of international tourism demand on economic growth of small economies dependent on tourism

This paper studies the impacts on economic growth of a small tourism-driven economy caused by an increase in the growth rate of international tourism demand. We present a formal model and empirical evidence. The ingredients of the dynamic model are a large population of intertemporally optimizing agents and an AK technology representing tourism production. The model shows that an increase in the growth of tourism demand leads to transitional dynamics with gradually increasing economic growth and increasing terms of trade. In our empirical application, an econometric methodology is applied to annual data of Antigua and Barbuda from 1970 to 2008. We perform a cointegration analysis to look for the existence of a long-run relationship among variables of economic growth, international tourism earnings and the real exchange rate. The exercise confirms the theoretical findings.