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   137393篇
  免费   3235篇
  国内免费   14篇
财政金融   25695篇
工业经济   11603篇
计划管理   21840篇
经济学   29459篇
综合类   1543篇
运输经济   976篇
旅游经济   2507篇
贸易经济   23608篇
农业经济   6210篇
经济概况   16942篇
信息产业经济   7篇
邮电经济   252篇
  2021年   845篇
  2020年   1633篇
  2019年   2394篇
  2018年   2323篇
  2017年   2530篇
  2016年   2709篇
  2015年   2105篇
  2014年   3435篇
  2013年   15360篇
  2012年   4214篇
  2011年   4163篇
  2010年   3738篇
  2009年   4346篇
  2008年   3953篇
  2007年   3294篇
  2006年   3624篇
  2005年   3610篇
  2004年   3142篇
  2003年   2918篇
  2002年   2878篇
  2001年   2652篇
  2000年   2557篇
  1999年   2441篇
  1998年   2323篇
  1997年   2360篇
  1996年   2205篇
  1995年   2011篇
  1994年   2013篇
  1993年   1992篇
  1992年   2042篇
  1991年   1952篇
  1990年   1836篇
  1989年   1686篇
  1988年   1613篇
  1987年   1613篇
  1986年   1702篇
  1985年   2496篇
  1984年   2357篇
  1983年   2162篇
  1982年   2015篇
  1981年   1948篇
  1980年   1917篇
  1979年   1856篇
  1978年   1636篇
  1977年   1623篇
  1976年   1393篇
  1975年   1281篇
  1974年   1193篇
  1973年   1190篇
  1972年   899篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Replacement investment is essentially a regenerative optimal stopping problem; that is, the key decision concerns when to terminate the life of existing plant – and hence when to start over again. This paper examines this optimisation problem within a continuous time framework and studies the qualitative and quantitative impact of uncertainty on the timing of new investment (and the criteria that should be used for terminating the life of existing plant).  相似文献   
82.
The speed with which communist China has embuaced markets has surprised Western analysis and observers, But Chinese economic progress will founder in corruption and inefficiency, argues Professor Steven Cheung of the university of Hong Kong, untess she insitutes a well-defined system of private property rights to safeguord investment and stimulate trade.  相似文献   
83.
Abstract:   The microstructure literature models the mechanisms through which fundamental information is incorporated into market prices. This paper extends previous models by endogenising information production and analysing incentives for costly information production. In contrast to the existing literature, increasing the number of informed traders can result in reduced price informativeness. When prices have an allocative role this has welfare consequences: the regulatory implications of a dichotomy between private and public incentives for information gathering are discussed.  相似文献   
84.
In the presence of foreign factor ownership tariffs change not only the terms of (goods) trade but also income flows between countries. Assume that only the home country owns factors abroad. Then the optimal tariff is negative if and only if foreign factor ownership entails trade-pattern reversals. Trade-pattern reversals are neither a necessary nor a sufficient condition for a negative optimal tariff if the foreign country owns factors in the home country. Changes in the home country's tariff shift the foreign country's offer curve. This adds a new dimension to optimal tariff analysis.  相似文献   
85.
Abstract. This research re-examines whether there are differences in the forecast accuracy of financial analysts through a comparison of their annual earnings per share forecasts. The comparison of analyst forecast accuracy is made on both an ex post (within sample) and an ex ante (out of sample) basis. Early examinations of this issue by Richards (1976), Brown and Rozeff (1980), O'Brien (1987), Coggin and Hunter (1989), O'Brien (1990), and Butler and Lang (1991) were ex post and suggest the absence of analysts who can provide relatively more accurate forecasts over multiple years. Contrary to the results of prior research and consistent with the belief in the popular press, we document that differences do exist in financial analysts' ex post forecast accuracy. We show that the previous studies failed to find differences in forecast accuracy due to inadequate (or no) control for differences in the recency of forecasts issued by the analysts. It has been well documented in the literature that forecast recency is positively related to forecast accuracy (Crichfield, Dyckman, and Lakonishok 1978; O'Brien 1988; Brown 1991). Thus, failure to control for forecast recency may reduce the power of tests, making it difficult to reject the null hypothesis of no differences in forecast accuracy even if they do exist. In our analysis, we control for the differences in recency of analysts' forecasts using two different approaches. First, we use an estimated generalized least squares estimation procedure that captures the recency-induced effects in the residuals of the model. Second, we use a matched-pair design whereby we measure the relative forecast accuracy of an analyst by comparing his/her forecast error to the forecast error of another randomly selected analyst making forecasts for the same firm in the same year on or around the same date. Using both approaches, we find that differential forecast accuracy does exist amongst analysts, especially in samples with minimum forecast horizons of five and 60 trading days. We show that these differences are not attributable to differences in the forecast issuance frequency of the financial analysts. In sum, after controlling for firm, year, forecast recency, and forecast issuance frequency of individual analysts, the analyst effect persists. To validate our findings, we examine whether the differences in the forecast accuracy of financial analysts persist in holdout periods. Analysts were assigned a “superior” (“inferior”) status for a firm-year in the estimation sample using percentile rankings on the distribution of absolute forecast errors for that firm-year. We use estimation samples of one- to four-year duration, and consider two different definitions of analyst forecast superiority. Analysts were classified as firm-specific “superior” if they maintained a “superior” status in every year of the estimation sample. Furthermore, they were classified as industry-specific “superior” if they were deemed firm-specific “superior” with respect to at least two firms and firm-specific “inferior” with respect to no firm in that industry. Using either definition, we find that analysts classified as “superior” in estimation samples generally remain superior in holdout periods. In contrast, we find that analysts identified as “inferior” in estimation samples do not remain inferior in holdout periods. Our results suggest that some analysts' earnings forecasts should be weighted higher than others when formulating composite earnings expectations. This suggestion is predicated on the assumption that capital markets distinguish between analysts who are ex ante superior, and that they utilize this information when formulating stock prices. Our study provides an ex ante framework for identifying those analysts who appear to be superior. When constructing weighted forecasts, a one-year estimation period should be used because we obtain the strongest results of persistence in this case.  相似文献   
86.
87.
Numerous labor-management issues possess ethical dimensions and pose ethical questions. In this article, the authors discuss four labor-management issues that present important contemporary problems: union organizing, labor-management negotiations, employee involvement programs, and union obligations of fair representation. In the authors view, labor and management too often view their ethical obligations as beginning and ending at the law's boundaries. Contemporary business realities suggest that cooperative and enlightened modes of interaction between labor and management seem appropriate.Robert S. Adler is Associate Professor of Legal Studies at the Kenan-Flagler Business School, University of North Carolina at Chapel Hill. He teaches courses in Business Law, Business Ethics, and Regulation. Prior to coming to UNC, Professor Adler served as Counsel to the Subcommittee on Health and the Environment of the Committee on Energy and Commerce of the U.S. House of Representatives.William J. Bigoness is Professor of Business Administration and Director, Center for Management Studies at the Kenan-Flagler Business School, University of North Carolina at Chapel Hill. His professional interests include organizational behavior, human resource management, and labor-management relations. Dr. Bigoness was Visiting Professor of Business Administration at the International Institute for Management Development (IMD) located in Lausanne, Switzerland from 1985 to 1987.  相似文献   
88.
89.
90.
This paper contributes to the productivity literature in developing country agriculture by quantifying the level of efficiency for a sample of peasant farmers from Eastern Paraguay. A stochastic efficiency decomposition methodology is used to derive technical, allocative and economic efficiency measures separately for cotton and cassava. An average economic efficiency of 40.1% for cotton and of 52.3% for cassava is found, which suggests considerable room for productivity gains for the farms in the sample through better use of available resources given the state of technology. Gains in output through productivity growth have become increasingly important to Paraguay as the opportunities to bring additional virgin lands into cultivation have significantly diminished in recent years. No clear strategy to improve farm productivity could be gleaned from an examination of the relationship between efficiency and various socioeconomic variables. One possible explanation for this finding is the existence of a stage of development threshold below which there is no consistent relationship between socioeconomic variables and productivity. If this is the case, then our results suggest that this sample of Paraguayan peasants are yet to reach such a threshold. Hence, improvements in educational and extension services, for example, would be needed to go beyond this threshold. Once this is accomplished, additional productivity gains would be obtained by further investments in human capital and related factors.  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