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   275篇
  免费   14篇
财政金融   47篇
工业经济   13篇
计划管理   62篇
经济学   71篇
综合类   2篇
运输经济   3篇
旅游经济   3篇
贸易经济   57篇
农业经济   16篇
经济概况   13篇
邮电经济   2篇
  2024年   1篇
  2023年   5篇
  2022年   2篇
  2021年   7篇
  2020年   8篇
  2019年   8篇
  2018年   14篇
  2017年   21篇
  2016年   8篇
  2015年   5篇
  2014年   8篇
  2013年   44篇
  2012年   15篇
  2011年   16篇
  2010年   13篇
  2009年   10篇
  2008年   14篇
  2007年   11篇
  2006年   5篇
  2005年   8篇
  2004年   6篇
  2003年   8篇
  2002年   8篇
  2001年   8篇
  2000年   8篇
  1999年   5篇
  1998年   2篇
  1997年   2篇
  1996年   3篇
  1995年   1篇
  1993年   3篇
  1992年   1篇
  1991年   1篇
  1986年   1篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1978年   1篇
  1976年   2篇
  1963年   1篇
排序方式: 共有289条查询结果,搜索用时 31 毫秒
81.
ABSTRACT

This paper addresses a road transport policy of allowing high capacity vehicles (HCVs) on the roads. The purpose is to examine the effect reduced road transport costs from HCVs can have on a modal shift. Two studies of HCV implementation in Sweden were combined. A micro-based case study modelled the distribution network of a major retailer in scenarios based on actual cost and flow data. A macro analysis was conducted of the cross-elasticity between rail and road combined with detailed price changes for lorries considering the product characteristics in different industries. The results show the long-term effects of HCVs on the modal shift for heavier, and heavier and longer vehicles. The combined approach triangulates the results and highlights the effects of logistics decision-making, transport network characteristics, and time. It emphasises linkages between modal shift and road transport efficiency, price reductions, geographical characteristics, product types, train organisation, and the capacity of HCVs.  相似文献   
82.
The use of digital methods offers a chance to connect communication science with economics. In recent years, a growing body of research in economics has turned its attention to media content, assuming that journalistic coverage contains hitherto neglected information relevant for business cycles or financial market movements. Interestingly, these approaches largely ignore communication science’s established theories and empirical findings. This paper aims at building a bridge between the two disciplines. Its contribution is threefold: a) it provides an overview of the most important approaches in economics that incorporate media content; b) it operationalizes the concept of the “narrative”, as it is used in economics, and distinguishes it from the concept of the “frame”, essential in communication science; c) exemplifying our approach, we present a new Uncertainty Perception Indicator (UPI) based on the topic modeling method Latent Dirichlet Allocation (LDA), that enables us to isolate different factors of economic policy uncertainty contained in media coverage.Economic studies treat journalistic media content as a proxy for sentiment prevalent in society. Typically, they rely on frequency analyses of certain keywords, like “recession” or “inflation”. Even more sophisticated approaches, such as Shiller (2017), who calls for establishing a new branch of “narrative economics”, or Baker et al. (2016), who construct a comprehensive set of media-based indicators, make no or little reference to communication science. This neglect could be discounted as pure ignorance, but this misses the point. Being a predominantly empirical discipline today, economics relies on long time-series of data, that have not been available for media content, a gap rendering the two disciplines largely incompatible.The gap is also reflected in terminology. “Frame” is a major analytical concept in communication science, while the term “narrative” has become in vogue in economics. Although both concepts are closely connected, they are rarely properly distinguished from each other. “Frame” can be considered as a rather static concept that applies during a limited period of time. “Narrative”, in contrast, implies dynamic properties, i.?e., the sorting of events, causes and effects over time, that explain how the current state of the world has come about, as stressed by Tenenboim-Weinblatt et al. (2016).In this paper, we propose a synergetic concept. Following Entman (1993), a media frame contains four elements: a) a problem definition, b) a problem diagnosis, c) a moral judgement, and d) possible remedies. We augment this approach by adding two more elements. According to our definition, a media narrative comprises a frame, or several ones, plus e) one or several protagonists—persons, institutions, or social groupings (nations, classes, etc.)—, whose relationships are (often) antagonistic and may change over time; and f) events, that are chronologically integrated and that are (often) assumed to constitute causal relationships. To put it metaphorically: a frame is to a narrative what a still photo is to a movie. Both are valuable concepts; the still photo shows more details, while the movie provides a contextualization over time.Topic models like LDA are valuable tools for the measurement of media narratives. The probabilistic approach enables researchers to conduct what may be called “macro-content analyses”, an exercise that focuses on average reporting patterns in large text corpora and can be translated into numerical time-series, thereby facilitating compatibility with empirical economics. Based on a topic’s frequency analysis, its top words and top articles, “mean media narratives” can be formulated, that integrate certain events, protagonists and frames.In our case study, we exemplify this concept by applying it to an indicator that is currently popular in economics, the Economic Policy Uncertainty Index (Baker et al. 2016). The EPU aims at capturing political developments that are exogenous to economic models and therefore unpredictable. Essentially, the indicator is based on the counts of articles containing a set of search words, such as “uncertain”, “economic” as well as institutions like the European Central Bank. Using identical search words as the EPU for Germany, we construct a similar corpus for the years 1994 to 2017. By conducting an LDA-based analysis, we are able to extract additional relevant information from the data. In particular, the evolution of different uncertainty factors and their development over time can be detected.Our Uncertainty Perception Indicator (UPI) contains six relevant news topics that are highly relevant for market developments: central banks, the national government, international politics, the business cycle, companies, and society. While the EPU merely shows how often uncertainty concerning economic policy is mentioned in the media, the UPI also indicates the origins of uncertainty. By grouping the six topics into three analytical categories—governments, markets, and society—we find a distinct break in the time-series. Before the financial crisis of 2008, the perception of uncertainty was rather balanced between the three factors. Since then, however, economic uncertainty has mainly been driven by political actors, most prominently by central banks. The corresponding narratives are a two-chapter story: in the first part, up to 2008, stable financial markets and smoothed business cycles prevailed, making central banking a rather straight-forward task. The second part is characterized by multiple crises, leaving central banks as dominant actors, that intervened with unconventional measures. Thereby, they became stabilizing forces, but at the same time sources of uncertainty with respect to the timing and the impact of these measures.  相似文献   
83.
Newly launched products in the consumer goods and services markets show high failure rates. To reduce the failure rates, companies can integrate innovative and knowledgeable customers, the so‐called lead users, into the new product development process. However, the detection of such lead users is difficult, especially in consumer product markets with very large customer bases. A new and potentially valuable approach toward the identification of lead users involves the use of virtual stock markets, which have been proposed and applied for political and business forecasting but not for the identification of experts such as lead users. The basic concept of virtual stock markets is bringing a group of participants together via the Internet and allowing them to trade shares of virtual stocks. These stocks represent a bet on the outcome of future market situations, and their value depends on the realization of these market situations. In this process, a virtual stock market elicits and aggregates the assessments of its participants concerning future market developments. Virtual stock markets might also serve as a feasible instrument to filter out lead users, primarily for the following two reasons. First, a self‐selection effect might occur because sophisticated consumers with a higher involvement in the product of interest decide to participate in virtual stock markets. Second, a performance effect is likely to arise because well‐performing participants in virtual stock markets show a better understanding of the market than their (already self‐selected) fellow participants. So far, only limited information exists about these two effects and their relation to lead user characteristics. The goal of this paper is to analyze the feasibility of virtual stock markets for the identification of lead users. The results of this empirical study show that virtual stock markets can be an effective instrument to identify lead users in consumer products markets. Furthermore, the results show that not all lead users perform well in virtual stock markets. Hence, virtual stock markets allow identifying lead users with superior abilities to forecast market success.  相似文献   
84.
Rules,discretion, and international monetary and fiscal policy coordination   总被引:1,自引:1,他引:0  
This paper considers the implications of international policy coordination when both monetary and fiscal policy choices are endogenous. We show that a movement from insular monetary commitment to international monetary policy coordination will, if fiscal policies are not coordinated, produce higher output and public expenditure levels at the expense of higher inflation rates. We also show that the concurrent coordination of monetary and fiscal policies raises output and inflation while lowering public expenditure relative to a regime of monetary coordination alone. We conclude that the arguments for concurrent monetary and fiscal policy coordination fail to have a clear-cut theoretical basis.  相似文献   
85.
A note on Wick products and the fractional Black-Scholes model   总被引:1,自引:0,他引:1  
In some recent papers (Elliott and van der Hoek 2003; Hu and Øksendal 2003) a fractional Black-Scholes model has been proposed as an improvement of the classical Black-Scholes model (see also Benth 2003; Biagini et al. 2002; Biagini and Øksendal 2004). Common to these fractional Black-Scholes models is that the driving Brownian motion is replaced by a fractional Brownian motion and that the Itô integral is replaced by the Wick integral, and proofs have been presented that these fractional Black-Scholes models are free of arbitrage. These results on absence of arbitrage complelety contradict a number of earlier results in the literature which prove that the fractional Black-Scholes model (and related models) will in fact admit arbitrage. The objective of the present paper is to resolve this contradiction by pointing out that the definition of the self-financing trading strategies and/or the definition of the value of a portfolio used in the above papers does not have a reasonable economic interpretation, and thus that the results in these papers are not economically meaningful. In particular we show that in the framework of Elliott and van der Hoek 2003, a naive buy-and-hold strategy does not in general qualify as self-financing. We also show that in Hu and Øksendal 2003, a portfolio consisting of a positive number of shares of a stock with a positive price may, with positive probability, have a negative value.Received: August 2004, Mathematics Subject Classification (2000): 91B28, 60H05JEL Classification: G10Support of the first author from the Jan Wallander and Tom Hedelius foundation is gratefully acknowledged. The research of the second author is supported by the Swedish Research Council.  相似文献   
86.
Motivated by the new auction format in the England and Wales electricity market, as well as the recent debate in California, we characterize bidding behavior and market outcomes in uniform and discriminatory electricity auctions. Uniform auctions result in higher average prices than discriminatory auctions, but the ranking in terms of productive efficiency is ambiguous. The comparative effects of other market design features, such as the number of steps in suppliers' bid functions, the duration of bids, and the elasticity of demand are analyzed. We also consider the relationship between market structure and market performance in the two auction formats.  相似文献   
87.
The two main competing theories for the outward shift in the uv‐curve are investigated: increased separations from employment at a given employment level (reallocation) and decreased levels of hires, given unemployment and vacancies (mismatch). Shifts in the unemployment–vacancy (uv)‐curve and the hiring function are modelled by smooth transition functions, and the hypothesis of analogous shifts in the two curves is tested and accepted. This is interpreted as evidence in favour of the mismatch hypotheses.  相似文献   
88.
Merger Policies and Trade Liberalisation   总被引:3,自引:0,他引:3  
This paper is about the interactions between trade policy and a narrow but important aspect of competition policy, namely merger policy. We focus on links between merger policies and trade liberalisation. We put special emphasis on the topical issue of the role that international agreements such as the GATT play when merger policies are nationally chosen. Of particular concern is the possibility that liberalisation of international trade will induce countries to use competition policies to promote national interests at the expense of others.  相似文献   
89.
We explore whether audit partners’ attitude towards risk, as measured by their personal criminal convictions, are reflected in the composition of their client portfolios. Analyzing a unique dataset of Swedish audit partners’ criminal convictions, we find that the clients of audit partners with criminal convictions are characterized by greater financial, governance, and reporting risk than those of audit partners without criminal convictions. Also, clients of audit partners with criminal convictions pay larger audit fees, on average, than those of auditors without criminal convictions.  相似文献   
90.
In natural hazards management, it is important to understand what motivates people to act when they or their property are threatened by natural hazards. Despite the importance of both threat and coping appraisals for responses to threats, less is known about the relations between threat and coping appraisals when risk management is long term. The present study examined appraisals of threat (cognitive and emotional), personal resources (cost and self-efficacy), and strategies (response-efficacy) as predictors of proactive management responses (past behavior and future intention) among forest owners in Sweden by means of a questionnaire (n = 1482). A path analysis revealed that threat appraisals and response-efficacy were direct predictors of past risk management behavior and the intention to respond in the future. Appraisals of resources, including cost and self-efficacy, were indirectly – via forest susceptibility and threat appraisals – related to threat responses. Although the model displayed reasonable fit for both owners more and those less involved in forestry, the cognitive appraisals variable was not a significant predictor of responses among owners less involved in forestry. In the full sample, the examined model explained approximately 50% of the variance in threat appraisals, and 28 and 17% in future intention and past behavior, respectively. Theoretical implications for how threat and coping appraisals are related during long-term risk management, and practical implications for forest risk management, are discussed.  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