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   12722篇
  免费   648篇
  国内免费   205篇
财政金融   2045篇
工业经济   577篇
计划管理   1910篇
经济学   2887篇
综合类   1368篇
运输经济   122篇
旅游经济   250篇
贸易经济   1594篇
农业经济   1513篇
经济概况   1308篇
信息产业经济   1篇
  2024年   18篇
  2023年   250篇
  2022年   167篇
  2021年   317篇
  2020年   551篇
  2019年   423篇
  2018年   399篇
  2017年   477篇
  2016年   490篇
  2015年   406篇
  2014年   695篇
  2013年   1218篇
  2012年   860篇
  2011年   997篇
  2010年   740篇
  2009年   731篇
  2008年   851篇
  2007年   732篇
  2006年   769篇
  2005年   573篇
  2004年   424篇
  2003年   336篇
  2002年   261篇
  2001年   205篇
  2000年   153篇
  1999年   92篇
  1998年   98篇
  1997年   89篇
  1996年   62篇
  1995年   45篇
  1994年   40篇
  1993年   28篇
  1992年   21篇
  1991年   14篇
  1990年   1篇
  1989年   4篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   8篇
  1984年   9篇
  1983年   8篇
  1982年   2篇
  1981年   2篇
  1979年   1篇
  1978年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Innovation clusters combining public and private effort to develop breakthrough technologies promise greater technological advances to slow down climate change. We use a multi-country model with an emission trading system to examine whether and how international climate policy can incentivize countries to create such innovation clusters. We find that a minimal carbon price is needed to attract applied research firms, but countries may nevertheless fail to invest in complementary research infrastructure. We construct a mechanism that leads to innovation clusters when emissions targets are set before uncertainty surrounding technological developments is resolved. It is a combination of low permit endowments for the country with the lowest costs to build the needed infrastructure, compensation for this country by profits from permit trade, and maximal possible permit endowments for the remaining countries. We outline how the EU-ETS can be further refined according to this mechanism.  相似文献   
2.
This note updates the 2019 review article “Retail forecasting: Research and practice” in the context of the COVID-19 pandemic and the substantial new research on machine-learning algorithms, when applied to retail. It offers new conclusions and challenges for both research and practice in retail demand forecasting.  相似文献   
3.
The increase in weather and climate disasters in recent years has prompted an interest in analyzing their consequences and the mitigation and adaptation measures that can help minimize their potentially large impacts on individuals’ welfare. We match thirty-one billion-dollar disasters with individual survey data from the Behavioral Risk Factor Surveillance System to estimate the effect of extreme weather events on the subjective well-being of U.S. residents. Our results indicate that natural disasters have a negative and robust impact on subjective well-being in the affected communities, and that, on average, this impact peaks 6 months after the event, and then decays over time. We then investigate the attenuating impact of health care access, flood insurance, and governmental assistance programs and find a partial compensating role for risk-transfer and relief measures. We also find that stronger emotional and social support mitigates the negative impact of natural disasters.  相似文献   
4.
5.
This paper investigates the way that minimum tick size affects market quality based on an agent‐based artificial stock market. Our results indicate that stepwise and combination systems can promote market quality in certain aspects, compared with a uniform system. A minimal combination system performed the best to improve market quality. This is the first study to analyse tick size systems that remain at the theory stage and compare four types of system under the same experimental environment. The results suggests that a minimal combination system could be considered a new direction for market policy reform to improve market quality.  相似文献   
6.
基于玉米和大豆等粮食国际、国内价格历史数据,运用协整及误差修正模型、脉冲响应函数等方法,揭示国际粮价对国内粮价的传导作用及影响路径。理论分析表明,国际粮价通过进口直接路径、进口产品成本路径和进口替代路径等三个子路径传导至国内粮价。实证检验发现,国际大豆价格进口直接路径和进口产品成本路径传导均比较充分,即国际大豆价格会影响大豆进口价格,进而影响国内大豆价格,最终影响国内豆油价格;国际玉米价格进口直接路径和进口产品成本路径传导则不充分,国际玉米价格会影响玉米进口价格,但是对国内玉米价格和国内玉米淀粉价格影响程度较低;而在进口替代路径中,玉米和大豆的国际价格传导均不充分。我国应继续推进以提质增效为目标的农业供给侧结构性改革,加大粮食生产科技投入力度,调动农民种粮积极性,集中力量提高粮食供给质量和效率;坚持粮食进口仅为调剂国内供求余缺的方针,把握粮食安全的主动权;建立健全粮食市场的价格调控体系及风险防控体系,规避国际粮食市场剧烈波动对国内粮食市场的影响。  相似文献   
7.
This paper proposes an empirical model for analysing the dynamics of Bitcoin prices. To do this, we consider a vector error correction model over two overlapping periods: 2010–17 and 2010–19. Price discovery is achieved through the Gonzalo–Granger permanent‐transitory decomposition. The pricing factors are endogenous linear combinations of the S&P 500 index, gold price, a Google search variable associated to Bitcoin and a fear index proxied by the FED Financial Stress Index. Our empirical analysis shows that during the first period, a linear combination of four pricing factors describes the efficient Bitcoin price. The S&P 500 index and Google searches have a positive effect whereas gold prices and the fear index have a negative effect. In contrast, during the second period, the efficient price behaves idiosyncratically and can be only rationalised by individuals' search for information on the cryptocurrency. These findings provide empirical evidence on the presence of a correction in Bitcoin prices during the period 2018–19 uncorrelated to market fundamentals. We also show that standard empirical asset pricing models perform poorly for explaining Bitcoin prices.  相似文献   
8.
Uncertainties posed by climate change limit companies' ability to understand implications of global warming on business and society at large, hampering the adoption of tangible organizational responses to climate change. Understanding climate action thus requires to investigate influential factors of decision-making under uncertainty, which implies acknowledging managerial interpretations and perceptions about climate issues. Drawing insights from the literature on climate inaction and from corporate sustainability literature, the present study examines awareness of climate change and perceived exposure to climate risks as antecedents of corporate responses to climate change, drawing on a survey of managers of Italian manufacturing companies. In addition, the study tests the moderation of risk tolerance on the relation between perceived climate risk exposure and climate action, suggesting that risk attitudes are a significant factor of decision-making under climate uncertainty. The results support the hypothesis of the model and thus provide several contributions to the literature on business and climate change. Managerial implications and avenues for future research are also discussed.  相似文献   
9.
We examine the co-movement of the G7 stock returns with the numbers of confirmed COVID-19 cases and causalities based on daily data from December 31, 2019 to November 13, 2020. We employ the wavelet coherence approach to measure the impact of the numbers of confirmed cases and deaths on the G7 stock markets. Our findings reveal that both the number of confirmed COVID-19 cases and the number of deaths exhibit strong coherence with the G7 equity markets, although we find heterogeneous results for the Canadian and Japanese equity markets, in which the numbers of COVID-19 cases and the deaths exhibit only a weak relationship. This evidence is more pronounced in the long-term horizon rather than the short-term horizon. Moreover, the lead-lag relationship entails a mix of lead-lag relations across different countries. We present the implications of these findings for both policymakers and the international investment community.  相似文献   
10.
This paper explores the use of clustering models of stocks to improve both (a) the prediction of stock prices and (b) the returns of trading algorithms.We cluster stocks using k-means and several alternative distance metrics, using as features quarterly financial ratios, prices and daily returns. Then, for each cluster, we train ARIMA and LSTM forecasting models to predict the daily price of each stock in the cluster. Finally, we employ the clustering-empowered forecasting models to analyze the returns of different trading algorithms.We obtain three key results: (i) LSTM models outperform ARIMA and benchmark models, obtaining positive investment returns in several scenarios; (ii) forecasting is improved by using the additional information provided by the clustering methods, therefore selecting relevant data is an important preprocessing task in the forecasting process; (iii) using information from the whole sample of stocks deteriorates the forecasting ability of LSTM models.These results have been validated using data of 240 companies of the Russell 3000 index spanning 2017 to 2022, training and testing with different subperiods.  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