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1.
Machine learning (ML) methods are gaining popularity in the forecasting field, as they have shown strong empirical performance in the recent M4 and M5 competitions, as well as in several Kaggle competitions. However, understanding why and how these methods work well for forecasting is still at a very early stage, partly due to their complexity. In this paper, I present a framework for regression-based ML that provides researchers with a common language and abstraction to aid in their study. To demonstrate the utility of the framework, I show how it can be used to map and compare ML methods used in the M5 Uncertainty competition. I then describe how the framework can be used together with ablation testing to systematically study their performance. Lastly, I use the framework to provide an overview of the solution space in regression-based ML forecasting, identifying areas for further research.  相似文献   
2.
This work presents key insights on the model development strategies used in our cross-learning-based retail demand forecast framework. The proposed framework outperforms state-of-the-art univariate models in the time series forecasting literature. It has achieved 17th position in the accuracy track of the M5 forecasting competition, which is among the top 1% of solutions.  相似文献   
3.
We examine the relation between audit quality and audit firm tenure in the Iranian audit market, which is constrained by government policies that create intense competition for clients among many small audit firms. We develop arguments that these circumstances create cost pressures that entrench low audit quality and render auditors' plans more predictable to managers wishing to misstate their accounts. Using publicly available data for the audits of listed companies in Iran prior to mandatory audit firm rotation and the incidence of misstated financial reports identified by the Iranian Association of Certified Public Accountants Inspection Office, we find that the likelihood of a misstatement is lowest in the first two years of audit firm tenure. We also find that the likelihood of misstatement is not associated with the year preceding a mandatory audit firm rotation, suggesting outgoing auditor effort is not sensitive to the prospect of subsequent revelations of deficiencies. Although our results from a pre-mandatory rotation period show that frequent rotations appear to improve the financial reporting quality in our sample, we are wary of interpreting these results as support for the mandatory audit firm rotation policy in Iran. Rather, we suggest this is a peculiar consequence of deficiencies in audit quality inherent in the Iranian market.  相似文献   
4.
Our analysis is rooted in the notion that stockholders can learn about the fundamental value of any firm from observing the earnings reports of its rivals. We argue that such intraindustry information transfers, which have been broadly documented in the empirical literature, may motivate managers to alter stockholders’ beliefs about the value of their firm not only by manipulating their own earnings report but also by influencing the earnings reports of rival firms. Managers obviously do not have access to the accounting system of peer firms, but they can nevertheless influence the earnings reports of rival firms by distorting real transactions that relate to the product market competition. We demonstrate such managerial behavior, which we refer to as cross‐firm real earnings management, and explore its potential consequences and interrelation with the practice of accounting‐based earnings management within an industry setting with imperfect (nonproprietary) accounting information.  相似文献   
5.
This paper estimates a spatial autoregressive (SAR) model of price dispersion using publicly available internet bookselling data. It uses a semiparametric adaptive estimator that does not require the usual Gaussian assumption of maximum likelihood (ML) estimators. The results suggest that both price competition and seller heterogeneity are key drivers of the observed price dispersion. The paper finds that sellers with large sales volume, newly established sellers and US mainland states-based sellers tend to price lower. The identified significant spatial interaction is evidence of spatial price competition. Controlling for everything else, a seller asks a lower price when large sellers charge relatively high prices, which is also evidence of price-based selling and undercutting.  相似文献   
6.
本文选取2011—2018年度A股上市公司为研究样本,以具有竞争关系的同业公司间的高管连锁作为同业监督的渠道,检验了同业监督对目标公司违规的影响。研究发现:(1)同业监督能有效抑制目标公司违规倾向,且这一影响当且仅当连锁公司是同业公司时存在;(2)同业竞争是同业监督的基础,在行业集中度低和行业增长率低的行业中,同业监督对目标公司违规的抑制作用更强;(3)目标公司的政治关联会瓦解同业监督对公司违规的抑制作用;(4)区分违规行为类型后发现,同业监督对经营违规的抑制作用最强,对信息披露违规次之,对领导人违规几乎没有效果。本研究丰富了公司违规监督机制的内容,也提供了辩证看待高管同业兼任的新视角。  相似文献   
7.
我国林业扶贫工作的主要问题及优化措施研究   总被引:2,自引:0,他引:2  
林业扶贫是当前我国扶贫工作的重要内容。通过介绍开展林业扶贫工作的政策背景、理论背景以及经济背景,分析林业扶贫工作开展过程中存在的基础设施落后、针对性差等问题,提出了因地制宜,互联网+林业扶贫,鼓励社会资本进入扶贫工作、志智双扶等应对措施。  相似文献   
8.
This paper investigates the portfolio optimization under investor’s sentiment states of Hidden Markov model and over a different time horizon during the period 2004–2016. To compare the efficient portfolios of the Islamic and the conventional stock indexes, we have employed two approaches: the Bayesian and Markowitz mean-variance. Our findings reveal that the Bayesian efficient frontier of Islamic and conventional stock portfolios is affected by the investor’s sentiment state and the time horizon. Our findings also indicate that the investor’s sentiment regimes change the Islamic and the conventional optimal diversified portfolios.Moreover, the results show that the potential diversification benefits seem to be more important when using the Bayesian approach than when applying the Markowitz approach. This finding is valid for the bearish, depressed, bullish and calm states in Islamic stock markets. However, the diversification of potential portfolios is significant only for the bullish and the bubble states in the conventional financial markets.The findings of the study provided additional evidence for investors to exploit googling investor sentiment states to evaluate the portfolio performance and make an optimal portfolio allocation.  相似文献   
9.
We derive the asymptotic distribution for the LU decomposition, that is, the Cholesky decomposition, of realized covariance matrix. Distributional properties are combined with an existing generalized heterogeneous autoregressive (GHAR) method for forecasting realized covariance matrix, which will be referred to as a generalized HARQ (GHARQ) method. An out-of-sample forecast comparison of a real data set shows that the proposed GHARQ method outperforms other existing methods in terms of optimizing the variances of portfolios.  相似文献   
10.
When a region successfully attracts a firm by offering subsidies, the firm often commits itself to performance targets in terms of employment. In this paper, we interpret these firm‐specific targets as a consequence of incomplete information. We analyze a model of two regions that compete for a firm, assuming that the firm's productivity is ex ante unknown. We show that performance targets often induce overemployment in high‐productivity firms, and that tax credits are often superior to lump‐sum payments. Moreover, when regions differ in wage rates, the low‐wage region wins the bid and has a higher surplus than under complete information. Finally, we show that, under incomplete information, bidding might not lead to efficient firm location.  相似文献   
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