首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   307篇
  免费   22篇
财政金融   46篇
工业经济   28篇
计划管理   66篇
经济学   83篇
综合类   3篇
运输经济   4篇
旅游经济   1篇
贸易经济   50篇
农业经济   15篇
经济概况   33篇
  2024年   1篇
  2023年   2篇
  2022年   2篇
  2021年   4篇
  2020年   6篇
  2019年   10篇
  2018年   11篇
  2017年   15篇
  2016年   7篇
  2015年   9篇
  2014年   11篇
  2013年   29篇
  2012年   12篇
  2011年   12篇
  2010年   17篇
  2009年   14篇
  2008年   15篇
  2007年   19篇
  2006年   9篇
  2005年   9篇
  2004年   7篇
  2003年   7篇
  2002年   15篇
  2001年   6篇
  2000年   6篇
  1999年   5篇
  1998年   6篇
  1997年   10篇
  1996年   4篇
  1995年   5篇
  1994年   4篇
  1993年   3篇
  1992年   6篇
  1991年   4篇
  1990年   6篇
  1989年   2篇
  1988年   2篇
  1987年   2篇
  1986年   5篇
  1985年   3篇
  1983年   1篇
  1982年   2篇
  1978年   1篇
  1975年   2篇
  1974年   1篇
排序方式: 共有329条查询结果,搜索用时 15 毫秒
71.
We investigate technological change with regard to CO2 emissions by passenger cars, using a Free Disposal Hull methodology to estimate technological frontiers. We have a sample of cars available in the UK market in the period 2000–2007. Our results show that the rates of technological change (frontier movement) and diffusion (distance to frontier at the car brand level) differ substantially between segments of the car market. We conclude that successful policies should be aimed at the diffusion of best-practice technology, and take account of the different potential for further progress between different segments of the market (e.g. diesel vs. gasoline engines and small vs. large engines).
Bart VerspagenEmail:
  相似文献   
72.
In a classical conjoint choice experiment, respondents choose one profile from each choice set that has to be evaluated. However, in real life, the respondent does not always make a choice: often he/she does not prefer any of the options offered. Therefore, including a no-choice option in a choice set makes a conjoint choice experiment more realistic. In the literature, three different models are used to analyze the results of a conjoint choice experiment with a no-choice option: the no-choice multinomial logit model, the extended no-choice multinomial logit model, and the nested no-choice multinomial logit model. We develop optimal designs for the two most appealing of these models using the D-optimality criterion and the modified Fedorov algorithm and compare these optimal designs with a reference design, which is constructed while ignoring the no-choice option, in terms of estimation and prediction accuracy. We conclude that taking into account the no-choice option when designing a no-choice experiment only has a marginal effect on the estimation and prediction accuracy as long as the model used for estimation matches the data-generating model.  相似文献   
73.
Though there is a consensus that transport plays a central role in economic development, for the period before the eighteenth century there is a lack of strategic information for assessing the importance of road transport productivity changes in economic development. Transport prices in particular are crucial missing pieces of the puzzle. Sources rarely reveal information that meets the standards of reliable price history. However, it is possible to create a reliable transport price series on the basis of the transport of millstones to ducal mills in Brabant. Assessing the impact of the ‘transport productivity changes’ that can be inferred from this transport price series is a hazardous exercise. Moreover, as Masschaele has observed, land transport prices closely match general agricultural price trends. Land transport was essentially an agricultural service, determined both by cost (especially horse provender) and income effects. Transport price inflation was not demand‐led. However, while transport did not impede urbanization and economic growth, conversely, in sixteenth‐century Brabant—a highly urbanized region that experienced considerable growth in the volume of land transport—no significant land transport productivity gains were achieved.  相似文献   
74.
75.
Based on unique data we show that macro variables, the default rate and loss given default of bank loans share common cyclical components. The innovation in our model is the distinction between loans with either severe or mild losses. The variation in the proportion of these two types drives the cyclic behavior of the loss given default and constitutes the links with the default rate and macro variables. These links vary according to loan and borrower characteristics. During downturns, the proportion of defaults with severe losses increases, but the distribution of losses conditional on their being mild or severe does not change. although loans are monitored more closely than bonds and are more senior, the cyclical variation in their losses resembles those for bonds, albeit around a lower average level. This variation leads to an increase in the capital reserves required for loan portfolios.  相似文献   
76.
Phylogenetic trees are types of networks that describe the temporal relationship between individuals, species, or other units that are subject to evolutionary diversification. Many phylogenetic trees are constructed from molecular data that is often only available for extant species, and hence they lack all or some of the branches that did not make it into the present. This feature makes inference on the diversification process challenging. For relatively simple diversification models, analytical or numerical methods to compute the likelihood exist, but these do not work for more realistic models in which the likelihood depends on properties of the missing lineages. In this article, we study a general class of species diversification models, and we provide an expectation-maximization framework in combination with a uniform sampling scheme to perform maximum likelihood estimation of the parameters of the diversification process.  相似文献   
77.
On the basis of aggregate data for the early 1990s, we analyse the determinants of unemployment duration for laid‐off male workers in Wallonia (Belgium). Our results indicate that if ranking in recruitment occurs, the standard mixed proportional hazard specification can be too restrictive, leading to an overstatement of the extent of true negative duration dependence. We conclude that negative duration dependence is largely spurious. We also decompose the time variation of the hazard in (unobserved) compositional and direct cyclical and seasonal effects. We find counter‐cyclical variation in the quality of young workers, but none for the prime aged. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
78.
This article is concerned with indices of export volume and prices in Indonesia from 1823 to 1940. It discusses the sources from which the quantitative information on exports is derived. Previous indices are shown and their shortcomings are considered. Next, Laspeyres quantity indices and Paasche unit value and price indices for agricultural and total exports are presented. These indices are based on fixed weights for eight sub-periods. The paper also discusses the features and shortcomings of the more sophisticated Divisia index, and concludes with some remarks on the long-term trend of exports from Indonesia.  相似文献   
79.
Estimates on the relationship between concentration and R&D effort are shown to be sensitive to problems of aggregation and of adequate measurement of R&D in small firms. While estimates from the official R&D survey of the Netherlands show a highly significant linear relationship between concentration and R&D, comparable estimates from our R&D data base prove it to be insignificant. However, at a finer level of disaggregation and when our sample is split into sectors with low and high technological opportunities, we discover evidence of a quadratic relationship in the latter and evidence of a weak linear relationship in the former.  相似文献   
80.
Fritjof Capra has become internationally known through two pioneering books, both best sellers, titled The Tao of Physics and The Turning Point. His third book, Green Politics which he wrote with Charlene Spretnak, was published in May 1984. The central theme which runs through all his work is the paradigmatic change in the Western view of the world. This article is taken from several conversations which Bart van Steenbergen had with Fritjof Capra. It begins with some background information and then looks at Fritjof Capra's work over the past 15 years.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号