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1.
Bio-economic modelling has become a useful tool for anticipating the outcomes of policies and technologies before their implementation. Advances in mathematical programming have made it possible to build more comprehensive models. In an overview of recent studies about bio-economic models applied to land-use problems in agriculture and forestry, we evaluated how aspects such as uncertainty, multiple objective functions, system dynamics and time have been incorporated into models. We found that single objective models were more frequently applied at the farm level, while multiple objective modelling has been applied to meet concerns at the landscape level. Among the objectives, social aspects are seldom represented in all models, when being compared to economic and environmental aspects. The integration of uncertainty is occasionally a topic, while stochastic approaches are more frequently applied than non-stochastic robust methods. Most multiple-objective models do not integrate uncertainty or sequential decision making. Static approaches continue to be more recurrent than truly dynamic models. Even though integrating multiple aspects may enhance our understanding of a system; it involves a tradeoff between complexity and robustness of the results obtained. Land-use models have to address this balance between complexity and robustness in order to evolve towards robust multiple-objective spatial optimization as a prerequisite to achieve sustainability goals.  相似文献   
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We comprehensively analyze the predictive power of several option-implied variables for monthly S&P 500 excess returns and realized variance. The correlation risk premium (CRP) and the variance risk premium (VRP) emerge as strong predictors of both excess returns and realized variance. This is true both in- and out-of-sample. Our results also reveal that statistical evidence of predictability does not necessarily lead to economic gains. However, a timing strategy based on the CRP leads to utility gains of more than 5.03% per annum. Forecast combinations provide stable forecasts for both excess returns and realized variance, and add economic value.  相似文献   
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Abstract Compared to other industrialized economies Ireland has been slow to privatize state‐owed enterprises. The first divestitures in 1991 failed to trigger a systematic programme of sell‐offs due to fears of job losses in an economy characterized by low rates of growth and high levels of unemployment. Where subsequent sales occurred they took place on a pragmatic and case‐by‐case basis with the reasons for privatization varying across companies. Some of the earlier sales took place because the enterprises were financially unviable whereas more recent sales can be attributed to the influence of EU policy on competition and restrictions on state aids. Since the privatization of the state telecommunications company in 1999 there has been a significant increase in privatization activity and most of the remaining public enterprises are candidates for divestiture. By 2001 total revenues amounted to €8.1 bn (9 per cent of GNP for 2001). A consistent justification for privatization has been that a change in ownership will lead to improved performance. The analysis in this paper fails to support this argument. At this early stage of the programe the experience has been for cost‐cutting measures to lead to improved performance prior to privatization with little evidence of continued improvements after divestiture .  相似文献   
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This paper contributes to the understanding of the long-run consequences of Roman rule on economic development. In ancient times, the area of contemporary Germany was divided into a Roman and a non-Roman part. The study uses this division to test whether the formerly Roman part of Germany are more developed than the non-Roman part. This is done using the Limes Germanicus wall as geographical discontinuity in a regression discontinuity design framework. The results indicate that economic development—as measured by luminosity—is indeed significantly and robustly larger in the formerly Roman part of Germany. The study identifies the persistence of the Roman road network until the present as an important factor causing this developmental advantage of the formerly Roman part of Germany both by fostering city growth and by allowing for a denser road network.  相似文献   
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Start-ups face branding challenges. Not only are they confronted with the task of building brands from scratch, their newness also leads to a particularly high amount of customer uncertainty. This paper contributes to the emerging field of entrepreneurial branding by investigating start-up characteristics that signal trustworthy information to potential customers. An extended choice-based conjoint approach for modeling brand equity is used to explore the impact of different signals as initiated by established and new firms in the field of tablet computers. An empirical study reveals brand signals that have significant effects on purchase probabilities and are appropriate to overcome information asymmetries between start-ups and prospective customers.  相似文献   
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Which factors facilitate the identification of business opportunities for sustainable development? To answer this question, we develop a process model of sustainable opportunity identification. We argue that sustainable opportunity identification is a process with transitions from problem to solution identification and from solution to sustainable opportunity identification. Moreover, the transitions are facilitated by two factors—awareness of adverse consequences and entrepreneurial attitude—providing motivation and direction in the process. We tested our model in a field study (N = 107) and two experiments (N = 53 and N = 69). Our findings show that awareness of adverse consequences and entrepreneurial attitude influence the process of sustainable opportunity identification, explaining under which conditions people are more likely to identify business opportunities for sustainable development. Our study thus contributes to the field of sustainable entrepreneurship.  相似文献   
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Ensemble methods can be used to construct a forecast distribution from a collection of point forecasts. They are used extensively in meteorology, but have received little direct attention in economics. In a real-time analysis of the ECB’s Survey of Professional Forecasters, we compare ensemble methods to histogram-based forecast distributions of GDP growth and inflation in the Euro Area. We find that ensembles perform very similarly to histograms, while being simpler to handle in practice. Given the wide availability of surveys that collect point forecasts but not histograms, these results suggest that ensembles deserve further investigation in economics.  相似文献   
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