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   1916篇
  免费   68篇
财政金融   312篇
工业经济   158篇
计划管理   399篇
经济学   425篇
综合类   16篇
运输经济   17篇
旅游经济   24篇
贸易经济   376篇
农业经济   53篇
经济概况   200篇
邮电经济   4篇
  2023年   11篇
  2022年   16篇
  2021年   24篇
  2020年   28篇
  2019年   46篇
  2018年   66篇
  2017年   53篇
  2016年   98篇
  2015年   57篇
  2014年   100篇
  2013年   267篇
  2012年   88篇
  2011年   93篇
  2010年   91篇
  2009年   90篇
  2008年   72篇
  2007年   75篇
  2006年   46篇
  2005年   40篇
  2004年   37篇
  2003年   47篇
  2002年   40篇
  2001年   28篇
  2000年   44篇
  1999年   49篇
  1998年   35篇
  1997年   25篇
  1996年   15篇
  1995年   19篇
  1994年   25篇
  1993年   22篇
  1992年   12篇
  1991年   14篇
  1990年   13篇
  1989年   11篇
  1988年   8篇
  1987年   10篇
  1986年   14篇
  1985年   16篇
  1984年   18篇
  1983年   14篇
  1982年   10篇
  1981年   12篇
  1980年   11篇
  1979年   8篇
  1978年   13篇
  1977年   5篇
  1976年   6篇
  1973年   5篇
  1972年   7篇
排序方式: 共有1984条查询结果,搜索用时 375 毫秒
1.
Past research has reported that learning processes in early stage R&D are either chaotic, or absent. We challenge this finding by elaborating Van de Ven et al.’s trial‐and‐error learning model and explore an alternative conceptualization. We explored the combinations of positive and negative outcomes and action course continuation and modification. We use data gathered in an R&D setting of a 4‐years pre‐competitive knowledge generation project in the Dutch paper and board industry. Whereas the Van de Ven and Polley (1992) approach applied on our data also would lead us to conclude that ‘no learning’ would happen, our decomposed model identified three distinct learning patterns: (1) a virtuous pattern of positive outcomes resulting in continuations of action courses; (2) a vacuous pattern of negative outcomes resulting in modifications of action courses; and (3) a verification pattern of positive outcomes resulting in modifications of action courses. We observed the virtuous and verification patterns during the first 2 years and virtuous and vacuous learning in the second 2 years. These results might be useful for R&D managers since they provide insight into how an early stage R&D project can develop and where managers might intervene and adjust action courses.  相似文献   
2.
How does the exposure to product market competition affect the investment horizon of firms? We study if firms have an incentive to shift investments toward more short‐term assets when exposed to tougher competition. Based on a stylized firm investment model, we derive a within‐firm estimator using variation across investments with different durabilities. Exploiting the Chinese World Trade Organization (WTO) accession, we estimate the effects of product market competition on the composition of US firm investments. Firms that experienced tougher competition shifted their expenditures toward investments with a shorter durability. This effect is larger for firms with lower total factor productivity.  相似文献   
3.
Estimation of expected return is required for many financial decisions. For example, an estimate for cost of capital is required for capital budgeting and cost of equity estimates are needed for performance evaluation based on measures such as EVA. Estimates for expected return are often based on the Capital Asset Pricing Model (CAPM), which states that expected excess return (expected return minus the risk-free rate) is equal to the asset's sensitivity to the world market portfolio (β) times the risk premium on the “world market portfolio” (the market risk premium). Since the world market portfolio, by definition, contains all assets in the world, it is not observable. As a result, an estimate for expected return is commonly obtained by taking an estimate for β based on some index (as a proxy for the world market portfolio) and an estimate for the market risk premium based on a potentially different index and multiplying them together. In this paper, it is shown that this results in a biased estimate for expected return. This is undesirable since biased estimates lead to misallocation of funds and biased performance measures. It is also shown in this paper that the straightforward procedure suggested by Fama and MacBeth [J. Financ. Econ. 1 (1974) 43] results in an unbiased estimate for expected return. Further from the analysis done, it follows that, for an unbiased estimate, it does not matter what proxy is used, as long as it is used correctly an unbiased estimate for expected return results.  相似文献   
4.
5.
6.
This article presents an application of Prezeworski and Teune's so-called “identity-equivalence method” to a large set of indicators of political participation. By relaxing commonly held assumptions about necessary distinctions among types of participation, it is found that the distinction between “conventional” and “unconventional” modes of participation is unnecessary, while the distinction between “government” and “nongovernment” has some merit. The findings also lend further support to the claims of Prezeworski and Teune that the identity-equivalence method is preferable to the identical indicator method.  相似文献   
7.
On Conditional Density Estimation   总被引:1,自引:0,他引:1  
With the aim of mitigating the possible problem of negativity in the estimation of the conditional density function, we introduce a so-called re-weighted Nadaraya-Watson (RNW) estimator. The proposed RNW estimator is constructed by a slight modification of the well-known Nadaraya-Watson smoother. With a detailed asymptotic analysis, we demonstrate that the RNW smoother preserves the superior large-sample bias property of the local linear smoother of the conditional density recently proposed in the literature. As a matter of independent statistical interest, the limit distribution of the RNW estimator is also derived.  相似文献   
8.
Generally valid scientific explanations of observable social phenomena are still hardly available. By applying philosophical insights generated by Quine and derived from semiotics to social research methodology three kinds of context dependencies accompanying theory formation within social science are identified. The third context dependency is mostly not attended in theory formation about social phenomena thereby producing a ``connotation fallacy', which leaves almost all social theories undetermined and fallible. These context dependencies should be taken into account in the research design and be tested for using statistical criteria comprising a new methodology presented in this article.  相似文献   
9.
Many observers argue that informed and insider trading is widespread in the emerging financial markets of transition countries, yet rigorous treatment of this issue has been virtually non–existent. The current paper estimates the extent of informed trading on the Prague Stock Exchange (PSE) using intra–day transaction data. Our estimates confirm that the average share of informed trading is equal to 0.32, which is high relative to developed markets and varies considerably among stocks. Using the Easley et al. (1996) approach on the very best segment of the PSE we obtained a high average probability of informed trading. Since data used in this study cover the period after the major attempts to improve market regulations, our results indicate that the PSE needs further strengthening to recover credibility and to become a real source of corporate financing. JEL classification: G14, G15.  相似文献   
10.
This paper provides a macroeconomic perspective for governmentinterventions in banking crisis. Such crisis occur when a largenumber of banks fail to meet capital requirements or are insolvent.Using a macroeconomic model with financial intermediation, ouranalyis suggests that strict enforcement of capital-adequaterules suffices in prosperous periods. Capital requirements serveas an indicator for crises interventions in critical stateswhich may require interest rate intervention and restructuringof the banking industry. These policies can be reinforced byrandom bailouts and temporary financial relief, with a largepercentage of the costs being covered by current and futureowners of banks. (JEL D41, E4, G2)  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