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   13174篇
  免费   363篇
  国内免费   1篇
财政金融   2415篇
工业经济   1133篇
计划管理   2242篇
经济学   2878篇
综合类   188篇
运输经济   105篇
旅游经济   197篇
贸易经济   2246篇
农业经济   682篇
经济概况   1444篇
信息产业经济   1篇
邮电经济   7篇
  2021年   73篇
  2020年   140篇
  2019年   191篇
  2018年   224篇
  2017年   240篇
  2016年   237篇
  2015年   173篇
  2014年   255篇
  2013年   1282篇
  2012年   382篇
  2011年   432篇
  2010年   365篇
  2009年   423篇
  2008年   343篇
  2007年   392篇
  2006年   326篇
  2005年   261篇
  2004年   274篇
  2003年   259篇
  2002年   292篇
  2001年   246篇
  2000年   275篇
  1999年   236篇
  1998年   247篇
  1997年   243篇
  1996年   235篇
  1995年   204篇
  1994年   214篇
  1993年   209篇
  1992年   255篇
  1991年   235篇
  1990年   189篇
  1989年   160篇
  1988年   158篇
  1987年   196篇
  1986年   192篇
  1985年   266篇
  1984年   285篇
  1983年   266篇
  1982年   234篇
  1981年   231篇
  1980年   224篇
  1979年   238篇
  1978年   149篇
  1977年   145篇
  1976年   102篇
  1975年   131篇
  1974年   94篇
  1973年   93篇
  1971年   78篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
71.
Tracking programs have been criticized on the grounds that they harm disadvantaged children. The bulk of empirical research supports this view, but existing studies compare outcomes across students placed in different tracks. Track placement is likely to be endogenous with respect to student outcomes. We use a new strategy for overcoming the endogeneity of track placement and find no evidence that tracking hurts low-ability children. Previous studies have also been based on the assumption that students' enrollment decisions are unrelated to whether or not the school tracks. When we account for the possibility that tracking programs affect school choice, we find evidence that they may help low-ability children.  相似文献   
72.
Elicitation using multiple price list formats   总被引:2,自引:0,他引:2  
We examine the properties of a popular method for eliciting choices and values from experimental subjects, the multiple price list format. The main advantage of this format is that it is relatively transparent to subjects and provides simple incentives for truthful revelation. The main disadvantages are that it only elicits interval responses, and could be susceptible to framing effects. We consider extensions to address and evaluate these concerns. We conclude that although there are framing effects, they can be controlled for with a design that allows for them. We also find that the elicitation of risk attitudes is sensitive to procedures, subject pools, and the format of the multiple price list table, but that the qualitative findings that participants are generally risk averse is robust. The elicitation of discount rates appear less sensitive to details of the experimental design. Electronic Supplementary Material Supplementary material is available in the online version of this article at . JEL Classification C9, D81, D91 An erratum to this article is available at .  相似文献   
73.
Summary. This research studies the role of multivariate distribution structures on random asset returns in determining the optimal allocation vector for an expected utility maximizer. All our conclusions pertain for the set of risk averters. By carefully disturbing symmetry in the distribution of the, possibly covarying, returns, we ascertain the ordinal structure of the optimized allocation vector. Rank order of allocations is also established when a permutation symmetric random vector is mapped into the returns vector through location and scale shifts. It is shown that increased dispersion in the vectors of location and scale parameters benefit, ex-ante, investors as does a decrease in the rank correlation coefficient between the location and scale parameter vectors. Revealed preference comparative static results are identified for the location and scale vectors of asset returns. For most issues addressed, we arrive at much stronger inferences when a safe asset is available. Received: August 8, 2000; revised version: January 8, 2001  相似文献   
74.
75.
Beef cattle producers were surveyed in Texas and Nebraska to investigate perceptions of sources of risk, the effectiveness of risk management strategies, and interest in further risk management education, particularly production risk, using probit analysis. Important decision variables identified are age, prior use of risk management tools, previous attendances of risk management education, and risk aversion. Severe drought and cattle price variability are identified as primary risk factors with potential to affect farm income. Extremely cold weather and disease are of less importance. Understocking pasture and storing hay are perceived most effective as risk management options.  相似文献   
76.
Monopoly, competition and information acquisition   总被引:1,自引:0,他引:1  
An incumbent monopolist is uncertain about its linear demand, but can acquire public information at a cost. We determine how an entry threat affects the firm's information acquisition. If returns to scale are constant and the state-contingent demands become more dispersed as output increases, then entry reduces information acquisition. If, however, either the incumbent or entrant has increasing returns; or if the state-contingent demands are nonlinear or fail increasing dispersion, then entry can increase information. Finally, entry can hurt consumers. Although entry always increases output, it can decrease information. Consumers sometimes prefer a better informed monopoly to a duopoly.  相似文献   
77.
78.
In this paper we compare alternative asymptotic approximations to the power of the likelihood ratio test used in covariance structure analysis for testing the fit of a model. Alternative expressions for the noncentrality parameter (ncp) lead to different approximations to the power function. It appears that for alternative covariance matrices close to the null hypothesis, the alternative ncp's lead to similar values, while for alternative covariance matrices far from Ho the different expressions for the ncp can conflict substantively. Monte Carlo evidence shows that the ncp proposed in Satorra and Saris (1985) gives the most accurate power approximations.  相似文献   
79.
80.
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