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41.
Urban regions are important places of ecosystem service demands and, at the same time, are the primary source of global environmental impacts. Although there is broad agreement on the importance of incorporating the concept of ecosystem services into policy strategies and decision-making, the lack of a standardized approach to quantifying ecosystem services at the landscape scale has hindered progress in this direction. Moreover, tradeoffs between ecosystem services and the supply/demand ratio of ecosystem services in urban landscapes have rarely been investigated. In our paper, we present a method to quantify and map the supply and demand of three essential provisioning services - energy, food, and water - along the rural-urban gradient of the eastern German region Leipzig-Halle. This urban region has experienced significant socio-economic dynamics and land use changes since the German reunification in 1990. The results show that both the demand and the supply of ecosystem services changed considerably during the time span under consideration (1990-2007). We identified an increasing supply/demand ratio of food and water but a decreasing supply/demand ratio of energy. In addition, the pattern of ecosystem demands shows a levelling of rural-urban gradients, reflecting profound modifications of traditional rural-urban relationships. The changes of ecosystem service supply gradients are determined more by land use intensity, such as the intensification of agricultural production, than by land cover changes such as urban sprawl. The comparison of supply/demand ratios and rural-urban patterns of ecosystem services can help decision-makers in landscape management in striving for a sustainable balance between resource supply and demand.  相似文献   
42.
Rational expectations are often used as an argument against policy activism, as they may undermine or neutralize the policymaker’s actions. Although this sometimes happens, rational expectations do not always imply policy invariance or ineffectiveness. In fact, in certain circumstances rational expectations can enhance our power to control an economy over time. In those cases, policy announcements can be used to extend the impact of conventional policy instruments. We present a general forward-looking policy framework and use it to provide a formal rationale for testing when policymakers can and cannot expect to be able to manage expectations. To describe the relevance of our results applications are shown for policy design in small-open economies. Those are the cases where domestic policies are at their weakest and our ability to influence expectations most constrained.  相似文献   
43.
Review of Quantitative Finance and Accounting - This paper presents a data-driven complex network approach, to show similarities and differences—in terms of financial risks—between the...  相似文献   
44.
This paper analyzes the connection between innovation activities of companies – implemented before crisis – and their performance – measured at time of crisis. The companies listed in the STAR Market Segment of the Italian Stock Exchange are analyzed. Innovation is measured through the level of investments in total tangible and intangible fixed assets in 2006–2007, while performance is captured through growth – expressed by variations of sales, total assets and employees – profitability – through ROI or ROS – and productivity – through asset turnover or sales per employee in the period 2008–2010. The variables of interest are analyzed and compared through statistical techniques and by adopting cluster analysis. In particular, a Voronoi tessellation is also implemented in a varying centroids framework. In accord with a large part of the literature, we find that the behaviour of the performance of the companies is not univocal when they innovate.  相似文献   
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46.
Consistent with social motivation theory, prior research on managerial motivation suggests that effort is contagious across management team members. In this study, we draw on belongingness theory to develop a model on important boundary conditions to social motivation theory in the management team context. The model predicts that new venture managers react to their teammates’ higher effort levels by investing higher effort levels themselves primarily when they are confronted with a threat – namely, low venture performance and high environmental hostility – but that effort is less contagious when managers face little threat. We test our model with a sample of 103 new venture managers nested in 51 management teams in a longitudinal setting capturing managerial effort over 26 weeks. While we do not find a direct relationship between teammates’ effort and a new venture manager’s subsequent effort, we find support for the crucial role of threat in triggering the contagion of managerial effort. We discuss the contributions of our study for research on management teams, performance feedback, and entrepreneurial effort in new ventures.  相似文献   
47.
This paper discusses, estimates and formally compares the best known procedures for incorporating demographic variables into complete demand systems. In particular, a class of general procedures belonging to Gorman's family of ‘general linear household technologies’ is introduced. Estimation and comparison of different procedures make use of Italian household budget data for the years 1973–1992, incorporating a single demographic variable (family size) into a Generalized Quadratic Almost Ideal Demand System. In our empirical example, however, even the most general household technologies are unable to fully capture the behavioural heterogeneity shown by the data. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
48.
In developing countries the demand for products of animal origin is expected to grow rapidly in the coming years. Using data collected from 200 urban households this study examines the evolution of the dairy market in Ethiopia. In particular, this study suggests that although the Ethiopian dairy market remains extremely thin and volatile, the commercialization of processed dairy products through supermarkets is expanding and is expected to keep doing so in the foreseeable future. Increasing urbanization and corresponding changes in consumer preferences, behaviour and purchasing power are the identified causes for the rise of supermarket-processor dairy chains. This study shows also that emerging dairy chains provide new market opportunities to Ethiopian farmers, but the existence of retail-industrial monopolies and monopsonies jeopardize farmers’ economic benefits to a great extent. The study concludes with some implications for policy and further research.  相似文献   
49.
This paper reports the findings of two experimental investigations into the efficacy of a causal cognitive mapping procedure as a means for overcoming cognitive biases arising from the framing of strategic decision problems. In Study 1, final year management studies undergraduate students were presented with an elaborated strategic decision scenario, under one of four experimental conditions: positively vs. negatively framed decision scenarios, with prechoice vs. postchoice mapping task orders (i.e., participants were required to engage in cognitive mapping before or after making a decision). As predicted, participants in the postchoice mapping conditions succumbed to the framing bias whereas those in the prechoice mapping conditions did not. Study 2 replicated and extended these findings in a field setting, on a sample of senior managers, using a decision scenario that closely mirrored a strategic dilemma currently facing their organization. Taken together, the findings of these studies indicate that the framing bias is likely to be an important factor in strategic decision making, and suggest that cognitive mapping provides an effective means of limiting the damage accruing from this bias. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   
50.
This paper assesses the stochastic convergence of relative \(\hbox {CO}_{2}\) emissions within 28 OECD countries over the period 1950–2013. Using the local Whittle estimator and some of its variants we assess whether relative per capita \(\hbox {CO}_{2}\) emissions are long memory processes which, although highly persistent, may revert to their mean/trend in the long run thereby indicating evidence of stochastic convergence. Furthermore, we test whether (possibly) slow convergence or the complete lack of it may be the result of structural changes to the deterministics of each of the relative per-capita emissions series by means of the tests of Berkes et al. (Ann Stat 1140–1165, 2006) and Mayoral (Oxford Bull Econ Stat 74(2):278–305, 2012). Our results show relatively weak support for stochastic convergence of \(\hbox {CO}_2\) emissions, indicating that only between 30 and 40% of the countries converge to the OECD average in a stochastic sense. This weak evidence disappears if we enlarge the sample to include 4 out of the 5 BRICS, indicating that our results are not robust to the inclusion of countries which are experiencing rates of growth which are far larger than those of the OECD members. Our results also decisively indicate that a slow or lack of convergence is not the results of a structural break in the relative \(\hbox {CO}_{2}\) emissions series.  相似文献   
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