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121.
With increasing sophistication, economists have been estimating gravity equations for five decades. Robust evidence shows that borders and distance impede trade by much more than tariffs or transports costs can explain. We therefore advocate investigation of other sources of resistance, despite the greater difficult involved in measuring and modelling them. From our selective review of recent findings, a unifying explanation emerges. A legacy of historical isolation and conflict forged a world economy in which neither tastes nor information are homogeneously distributed. Cultural difference and inadequate information manifest themselves most strongly at national borders and over distance.  相似文献   
122.
In spite of the rapidly growing research on fiscal multipliers over recent years, little evidence has been so far accumulated in developing and emerging economies. This paper investigates the nature and the size of fiscal multipliers in Central and Eastern European (CEE) countries. Unlike most of the existing literature, we draw upon a panel vector error correction model, which appropriately captures the common long-term path of CEE countries, while allowing for different short-run dynamics, in an integrated setup. Our main results show that the spending multiplier is positive, but low on average. Moreover, its sign, significance and magnitude vary across CEE. Finally, both impulse and cumulative fiscal multipliers are sensitive to a wide range of CEE characteristics, including the exchange rate regime, the level of economic development, the fiscal stance and the openness degree.  相似文献   
123.
124.
The technique of reaction calorimetry adapted for use with reactions in supercritical fluids was used to study some safety aspects of the free-radical dispersion polymerization of methyl methacrylate in scCO2. The reaction heat rate profile was found to change very little once the dispersion was well formed. Furthermore, it provided valuable information for the calculation of the maximum temperature attainable by the synthesis reaction (MTSR) in the case of a hypothetical cooling system failure. Finally, a series of failure scenarios demonstrated the importance of the pressure as far as the safety of the process is concerned, due to the particularity of the supercritical state of the solvent. It was found that the acceleration phase of the reaction is the most critical period, since a cooling system failure during this phase leaves very little time before the pressure overcomes the operational limit of the equipment and results in an accident. Hence, the utility and the importance of defining the reaction heat rate profile become obvious and several safety features have to be taken into consideration when designing a SCF process. © 2009 American Institute of Chemical Engineers Process Saf Prog 2009  相似文献   
125.
This paper deals with the process through which relationships between public research laboratories and firms develop over time. Two case studies in France illustrate the lengthy and interactive process needed by laboratories and firms in learning to work together. Laboratories and firms need also to think about new R&D strategies and especially a new balance in their activities between research and development.  相似文献   
126.
The aim of this research is to explore the dynamics and impact of open social innovation, within the context of fab labs and makerspaces. Using an exploratory methodology based on 12 semi‐structured interviews of fab lab founders belonging to The Centres for Maker Innovation and Technology (CMIT) programme – a network of 170 fab labs located in Eastern Europe – this research explores the impact of an adopting an open approach in relation to the different stages of social innovation (prompts, proposals, prototypes, sustaining, scaling and diffusion, systemic change) as well as social impact. The main results of this study are that while the CMIT programme provided each fab lab with similar initial conditions (identical funding, objectives and rules), the open social innovation approached adopted enabled to give birth to a wide diversity of fab labs, each being very well adapted to the local environment, social needs and constraints and able to deliver social impact in just a matter of years; a result that would be hard to achieve with a centralised top‐down approach. The study identified three types of CMITs – Education, Industry and Residential – which could be similar or different depending on the stage of social open innovation. Furthermore, this paper discusses the main difficulties social entrepreneurs encounter as a part of the open social innovation process, as well as means to overcome them. In this respect, this study adds to the literature on fab labs by providing more comprehensive view of the challenges faced by fab labs (and makerspaces) founders, as well as suggestions of strategies enabling to ensure their long‐term sustainability.  相似文献   
127.
A 130–30 strategy is an attractive and viable equity investment strategy for building long–short portfolios and notionally expected to enhance investment exposure and market protection. However, the amalgamation of the strategy in the portfolio optimization problem model poses complex constraints which render the problem model difficult for solving using traditional methods, thus justifying the application of metaheuristic solutions. We discuss a metaheuristic and integrated optimization of long–short portfolios, when the 130–30‐strategy‐based constraint, besides other investor preferential constraints, is incorporated in the problem's formulation. In the absence of reported work and for reasons of performance comparison and analysis, two metaheuristic strategies have been proposed in order to solve the problem: (i) evolution strategy with hall of fame and (ii) differential evolution (rand/1/bin) with hall of fame. The experimental studies were undertaken on the Bombay Stock Exchange (BSE200) and Tokyo Stock Exchange (Nikkei 225) data sets and specifically for the period March 1999–March 2009, which included both upturns and downturns in the global markets. The efficiencies of the portfolios obtained by the two metaheuristic methods were analysed using an efficiency improvement possibility function, a portfolio productivity indicator which is a variation of Luenberger's shortage functions. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
128.
This paper studies the population dynamics of multiple preference traits in a model of intergenerational cultural transmission. Parents socialize and transmit their preferences to their children with endogenous intensities. Populations concentrated on a single cultural group are in general not stable. There is a unique stable stationary distribution, and it supports two or more cultural groups, in particular those with greater intolerance with respect to others' traits. The larger the heterogeneity of intolerance levels across cultural groups, the smaller the number of traits that are supported in the stable stationary distribution.  相似文献   
129.
In this article we attempt to uncover some systemic management principles for the better management of complex issues. Taking a pragmatic approach we have expanded the case methodology proposed by John Dewey to the case study of a major crisis. By proposing that crises allow for a better apprehension of complexity, we study the changes which were carried out or not, to this day, after the 1988 Nestucca oil spill that occurred in Canada only three months prior to the Exxon-Valdez disaster. After conducting a linear and systemic analysis of the crisis, we propose that the changes institutionalized thus far spring mostly from what we call “behavioral” and “paradigmatic” learning which are weak for addressing complex issues. Proposing that 15% of the people we have interviewed where able to derive a “systemic learning” from this crisis, we suggest several unlocking strategies that allow these systemic lessons to be institutionalized.  相似文献   
130.
This article shows that multiple growth paths may occurin a politico-economic model of endogenous growth. This multiplicityis characterized by the coexistence of the low-tax, low-capital-flightequilibrium and a high-tax, high-capital-flight equilibrium.The likelihood of multiplicity is crucially related to the structureof power in society—namely, it is necessary that the politicallydecisive agents have a greater access to international capitalmarkets than the average in the economy.  相似文献   
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