全文获取类型
收费全文 | 132篇 |
免费 | 10篇 |
专业分类
财政金融 | 22篇 |
工业经济 | 11篇 |
计划管理 | 34篇 |
经济学 | 37篇 |
运输经济 | 2篇 |
贸易经济 | 23篇 |
农业经济 | 5篇 |
经济概况 | 6篇 |
邮电经济 | 2篇 |
出版年
2023年 | 6篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 10篇 |
2018年 | 12篇 |
2017年 | 11篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 19篇 |
2012年 | 10篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2004年 | 1篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1977年 | 2篇 |
排序方式: 共有142条查询结果,搜索用时 12 毫秒
1.
Luz Maria Castro Fabian Härtl Santiago Ochoa Baltazar Calvas Leonardo Izquierdo Thomas Knoke 《Journal of Bioeconomics》2018,20(2):183-211
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
2.
3.
Fabian Wahl 《Journal of Economic Growth》2017,22(3):313-349
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
4.
Fabian Eggers Felix Eggers Sascha Kraus 《The International Entrepreneurship and Management Journal》2016,12(2):427-444
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
5.
Fabian Krüger 《Empirical Economics》2017,53(1):235-246
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
6.
7.
Fabian Bergès Daniel Hassan Sylvette Monier‐Dilhan 《Bulletin of economic research》2013,65(Z1):s1-s16
The evolution of private labels (PLs) can be understood in terms of a strategy adopted by the retail industry with the aim of competing with national brands (NBs). In the 1990s, this strategy led to the development of ‘me too’ products, which currently represent the largest share of store brand products. Since the early 2000s, retailers have widened the range of their store brands by introducing high‐quality products. The aim of this study was to estimate consumers’ attachment to ‘me‐too’ and niche PLs respectively, as compared to NBs. We captured the degree of maturity of these PLs through their price‐elasticities, computed for three staple goods offered by three mass retail companies. It was found that price sensitivity does not differ much between the ‘me‐too’ PLs and the corresponding NBs. This result confirms that ‘me‐too’ products are now considered reliable quality brands. However, in the high quality segment, consumers remain more sensitive to the price of PLs than to that of NBs, a characteristic which may relate to their recent introduction on the market. 相似文献
8.
Felix EggersAuthor Vitae Fabian EggersAuthor Vitae 《Technological Forecasting and Social Change》2011,78(1):51-62
With rising gas prices, global warming, and green thinking, all-electric vehicles are currently considered the automobile technology of the future. However, besides their advantages electric drive trains also exhibit several disadvantages. Moreover, history shows several failed attempts to establish electric vehicles. Thus, a reliable forecasting model is needed that predicts if the current trend is sustainable. We develop and empirically test a choice-based conjoint adoption model that uses individual-level preferences as a basis for prediction. Predictions are mapped to the time of the next planned purchase in order to establish the adoption process. The model extends existing research in several ways. First, no prior information, e.g., historical market data or a functional form of the adoption process, has to be integrated. Second, the model allows dynamic modifications of product specifications or competition at different points in time. Third, a no-choice option can be integrated so that a technology switch is not forced by the model itself and switching costs can be considered. The empirical results reveal different critical factors for the adoption of all-electric vehicles, such as purchase price, range, timing of the market entry, or environmental evolution, which could lead to a solid base of consumers preferring this option. 相似文献
9.
Fabian A. Ryffel 《Publizistik》2016,61(2):167-187
Regarding formal, linguistic and content-related characteristics, tabloid newspapers have a relatively high potential to emotionally arouse readers, whereas broadsheets present news in a more factual style. In the present study it is argued that the usage of the different types of newspapers affects attitude structures. Specifically, it is assumed that the frequency of usage and expected gratifications during usage have an effect on the affective-cognitive attitude basis. Results of a survey (N = 505) support the hypotheses on the emotion gap: Heavy users of broadsheets base their attitudes on cognitions, regardless of their expected gratifications. For heavy users of tabloid newspapers, expected gratifications moderate the effect of usage on attitude bases: Information-oriented tabloid recipients hold cognition-based attitudes; entertainment-oriented tabloid recipients hold affect-based attitudes. 相似文献
10.
Fabian Pfaffenberger 《Publizistik》2018,63(1):53-72
Twitter has a high presence in our modern society, media and science. Numbers of studies with Twitter data – not only in communication research – show that tweets are a popular data source for science. This popularity can be explained by the mostly free data and its technically high availability, as well as the distinct and open communication structure. Even though much research is based on Twitter data, it is only suitable for research to a limited extent. For example, some studies have already revealed that Twitter data has a low explanatory power when predicting election outcomes. Furthermore, the rise of automated communication by bots is an urgent problem of Twitter data analysis. Although critical aspects of Twitter data have already been discussed to some extent (mostly in final remarks of studies), comprehensive evaluations of data quality are relatively rare.To contribute to a deeper understanding of problems regarding the scientific use of Twitter data leading to a more deliberate und critical handling of this data, the study examines different aspects of data quality, usability and explanatory power. Based on previous research on data quality, it takes a critical look with the following four dimensions: availability and completeness, quality (regarding authenticity, reliability and interpretability), language as well as representativeness. Based on a small case study, this paper evaluates the scientific use of Twitter data by elaborating problems in data collection, analysis and interpretation. For this illustrative purpose, the author typically gathered data via Twitter’s Streaming APIs: 73,194 tweets collected between 20–24/02/2017 (each 8pm) with the Streaming APIs (POST statuses/filter) containing the search term “#merkel”.Concerning data availability and completeness, several aspects diminish data usability. Twitter provides two types of data gateways: Streaming APIs (for real-time data) and REST APIs (for historical data). Streaming APIs only have a free available Spritzer bandwidth, that is limited to only one percent of the overall (global) tweet volume at any given time. This limit is a prevalent problem when collecting Twitter data to major events like elections and sports. The REST APIs do not usually provide data older than seven days. Furthermore, Twitter gives no information about the total or search term-related tweet volume at any time.In addition to incomplete data, several quality related aspects complicate data gathering and analysis, like the lack of user specific and verified information (age, gender, location), inconsistent hashtag usage, missing conversational context or poor data/user authenticity. Geo data on Twitter is – if available at all – rarely correct and not useful for filtering relevant tweets. Searching and filtering relevant tweets by search terms can be deceptive, because not every tweet concerning a topic contains corresponding hashtags. Furthermore, it is difficult to find a perfect search term for broader and dynamically changing topics. Besides, the missing conversational context of tweets impedes interpretation of statements (especially with regard to irony or sarcasm). In addition, the rise of social bots diminishes dataset quality enormously. In the dataset generated for this work, only three of the top 30 accounts (by tweet count) could be directly identified as genuine. One fourth of all accounts in this dataset generated about 60% of all tweets. If the high-performing accounts predominantly consist of bots, the negative impact on data quality is immense.Another problem of Twitter analysis is Internet language. While Emojis can be misinterpreted, abbreviations, neologisms, mixed languages and a lack of grammar impede text analysis. In addition to low data quality in general, the quality of tweet content and its representativeness is crucial. This work compares user statistics with research articles on SCOPUS as well as media coverage of two selected, German quality newspapers. Twitter is – compared to its user count – enormously overrepresented in media and science. Only 16% of German adults (over 18 years) are monthly active (MAUs) and merely four percent are daily active users.Considering all presented problems, Twitter can be a good data source for research, but only to a limited extent. Researchers must consider that Twitter does not guarantee complete, reliable and representative data. Ignoring those critical points can mislead data analysis. While Twitter data can be suitable for specific case studies, like the usage and spread of selected hashtags or the twitter usage of specific politicians, you cannot use it for broader, nation-based surveys like the prediction of elections or the public opinion on a specific topic. Twitter has a low representativeness and is mostly an “elite medium” with an uncertain future (concerning the stagnating number of users and financial problems). 相似文献