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   10999篇
  免费   271篇
财政金融   1957篇
工业经济   816篇
计划管理   1913篇
经济学   2667篇
综合类   147篇
运输经济   82篇
旅游经济   135篇
贸易经济   1498篇
农业经济   513篇
经济概况   1486篇
邮电经济   56篇
  2020年   110篇
  2019年   183篇
  2018年   201篇
  2017年   245篇
  2016年   228篇
  2015年   134篇
  2014年   246篇
  2013年   1041篇
  2012年   293篇
  2011年   327篇
  2010年   259篇
  2009年   365篇
  2008年   289篇
  2007年   256篇
  2006年   227篇
  2005年   235篇
  2004年   202篇
  2003年   247篇
  2002年   205篇
  2001年   216篇
  2000年   233篇
  1999年   229篇
  1998年   205篇
  1997年   203篇
  1996年   183篇
  1995年   162篇
  1994年   173篇
  1993年   195篇
  1992年   200篇
  1991年   191篇
  1990年   192篇
  1989年   165篇
  1988年   155篇
  1987年   150篇
  1986年   173篇
  1985年   199篇
  1984年   195篇
  1983年   175篇
  1982年   161篇
  1981年   184篇
  1980年   162篇
  1979年   181篇
  1978年   148篇
  1977年   141篇
  1976年   127篇
  1975年   90篇
  1974年   101篇
  1973年   96篇
  1972年   72篇
  1971年   64篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
92.
We provide evidence on the impact of tax incentives and financial constraints on corporate R&D expenditure decisions. We contribute to extant research by comparing R&D expenditures in the United States and Canada, thereby exploiting the differences in the two countries' R&D tax credit mechanisms and generally accepted accounting principles. The two tax incentive mechanism designs are consistent with differing views of the degree of financial constraints faced by firms in these economies. Our sample also allows us to explore the effects of capitalizing R&D on Canadian firms. Employing a matched design, we document relations between tax credit incentives and R&D spending consistent with both Canadian and U.S. public companies responding as though they are not financially constrained. We estimate that the Canadian credit system induces, on average, $1.30 of additional R&D spending per dollar of taxes forgone while the U.S. system induces, on average, $2.96 of additional spending. We also find that firms that capitalize R&D costs in Canada spend, on average, 18 percent more on R&D. Collectively, this evidence is important to the ongoing debates in both countries concerning the appropriate design of incentives for R&D and is consistent with the assumptions found in the U.S. tax credit system, but not those found in the Canadian system.  相似文献   
93.
94.
On April 1, 1988, New Zealand stopped the double taxation of dividends by implementing a full dividend imputation program. Because many believed that the tax advantage of debt had led to more highly leveraged firms subject to greater financial risk than was socially optimal, it was hoped the removal of incentives to finance with debt would result in a more efficient allocation of capital. The empirical results suggest that the shareholder wealth gain from dividend imputation was more than offset in firms with large debt levels. Moreover, an examination of debt ratios indicates debt levels declined in the post–imputation period.  相似文献   
95.
Random urinalysis strategies stratified by time since the last test are characterized with a set of Markov chain models. The probability of a person being tested depends on the amount of time since the person's last test. The Nuclear Regulatory Commission (NRC) has proposed a two strata drug testing strategy based on time since last test. The proposal included a high testing rate for people not yet tested in a given time period and a low testing rate for people testing negative in a given time period. Southern California Edison has implemented a variation of the NRC proposal. These strategies can be modeled within a Markov chain framework. Time to detection is calculated as a function of testing probabilities and drug usage levels. Drug user gaming strategies are discussed with illustrations. These models are implemented as part of a U.S. Navy drug policy analysis system.  相似文献   
96.
97.
98.
Modeling Conditional Yield Densities   总被引:2,自引:0,他引:2  
Given the increasing interest in agricultural risk, many have sought improved methods to characterize conditional crop-yield densities. While most have postulated the Beta as a flexible alternative to the Normal, others have chosen nonparametric methods. Unfortunately, yield data tends not to be sufficiently abundant to invalidate many reasonable parametric models. This is problematic because conclusions from economic analyses, which require estimated conditional yield densities, tend not to be invariant to the modeling assumption. We propose a semiparametric estimator that, because of its theoretical properties and our simulation results, enables one to empirically proceed with a higher degree of confidence.  相似文献   
99.
The behaviour of stock prices on the Colombo Stock Exchange (CSE) is examined with a view to determine its consistency with the weak form of the Efficient Markets Hypothesis (EMH). Runs, Autocorrelation and Cointegration tests are applied to daily, weekly and monthly CSE index data for the period of January 1991–November 1996. Results of Runs, Correlation and Cointegration tests overwhelmingly reject the serial independence hypothesis, leading to the conclusion that the behaviour of stock prices in the Colombo Stock Exchange is not consistent with the weak form of the Efficient Markets Hypothesis. Tests of the-day-of-the-week-effect, however, show that there is no evidence of such a phenomenon on the Colombo Stock Exchange stock prices. Results of the tests of the-month-of-the-year-effect lead to the conclusion that CSE prices do not display any month-specific behaviour.  相似文献   
100.
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