全文获取类型
收费全文 | 1919篇 |
免费 | 283篇 |
专业分类
财政金融 | 97篇 |
工业经济 | 66篇 |
计划管理 | 91篇 |
经济学 | 503篇 |
综合类 | 11篇 |
运输经济 | 6篇 |
旅游经济 | 19篇 |
贸易经济 | 32篇 |
农业经济 | 1210篇 |
经济概况 | 167篇 |
出版年
2023年 | 6篇 |
2022年 | 8篇 |
2021年 | 23篇 |
2020年 | 77篇 |
2019年 | 140篇 |
2018年 | 66篇 |
2017年 | 103篇 |
2016年 | 93篇 |
2015年 | 86篇 |
2014年 | 120篇 |
2013年 | 154篇 |
2012年 | 160篇 |
2011年 | 240篇 |
2010年 | 136篇 |
2009年 | 143篇 |
2008年 | 144篇 |
2007年 | 138篇 |
2006年 | 110篇 |
2005年 | 109篇 |
2004年 | 27篇 |
2003年 | 30篇 |
2002年 | 19篇 |
2001年 | 20篇 |
2000年 | 10篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 11篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1990年 | 1篇 |
排序方式: 共有2202条查询结果,搜索用时 718 毫秒
111.
This paper proposes a nonparametric procedure to estimate market power for first‐price auction data and applies the procedure to cattle procurement markets. Most previous studies have used parametric methods, which require specific functional forms for retail demand, input supply and processors’ cost equations. However, researchers often find that market power estimates from parametric methods are sensitive to the choice of functional forms and specifications. An application to data from cattle procurement experiments shows that our nonparametric approach greatly outperforms commonly used parametric methods in estimating the degree of market power. While parametric estimates are sensitive to functional form specification and are at least 90% smaller than ‘true’ market power indices, estimates from our nonparametric procedure deviate from the actual value by no more than 25%. 相似文献
112.
This paper examines market integration between fish species in Europe, taking international market integration into account. Based on Juselius (2006) , market integration is found both on the fresh and frozen markets. The Law of One Price is in force on the fresh market within the segments of flatfish and pelagic fish. Assuming transitivity, a loose form of market integration is identified between 13 fresh and seven frozen fish species, and the relative prices are found fairly stable. The policy implication is that catch limitation measures implemented through the Common Fisheries Policy have limited and conditional effects on prices, because of the large size of the market and varying market integration. Therefore, many fishermen are not ‘compensated’ by price increases as a result of catch limitation measures. 相似文献
113.
Arega D. Alene Abebe Menkir S. O. Ajala B. Badu-Apraku A. S. Olanrewaju V. M. Manyong Abdou Ndiaye 《Agricultural Economics》2009,40(5):535-550
This article assembles the results of three multicountry surveys on variety performance and adoption patterns to measure the impacts of maize research in West and Central Africa from 1981 to 2005, and uses cost data since 1971 to compute social rates of return on public investments in maize research in the region. Adoption of modern varieties increased from less than 5% of the maize area in the 1970s to about 60% in 2005, yielding an aggregate rate of return on research and development (R&D) investment of 43%. The estimated number of people moved out of poverty through adoption of new maize varieties rose gradually in the 1980s to more than one million people per year since the mid 1990s. Over half of these impacts can be attributed to international maize research at IITA and CIMMYT. The article concludes with a discussion of strategic options to enhance the impacts of maize research in the region. 相似文献
114.
The dynamics of biomass growth implies that the yield of irrigated crops depends, in addition to the total amount of water applied, on irrigation scheduling during the growing period. Advanced irrigation technologies relax constraints on irrigation rates and timing, allowing us to better adjust irrigation scheduling to the varying needs of the plants along the growing period. Irrigation production functions, then, should include capital (or expenditures on irrigation equipment) in addition to aggregate water. We derive such functions and study their water-capital substitution properties. Implications for water demand and adoption of irrigation technologies are investigated. A numerical example illustrates these properties. 相似文献
115.
Does access to off-farm income complement or compete with agricultural production? This article explores the effect of off-farm income on agricultural production activities, using data from the 2003 Mexico National Rural Household Survey. We first discuss the theoretical conditions under which access to off-farm income may influence production in an agricultural household model. Instrumental-variable (IV) estimation methods are then used to test whether agricultural production activities, technologies, and input use differ between households with and without access to off-farm income. We find that off-farm income has a negative effect on agricultural output and the use of family labor on the farm, but a positive impact on the demand for purchased inputs. There is also a slight efficiency gain in households with access to off-farm income. Findings offer insights into how household production evolves as rural households increasingly engage in off-farm income activities. 相似文献
116.
Alan Swinbank 《Journal of Agricultural Economics》2009,60(3):485-503
The paper outlines EU policy on bioenergy, including biofuels, in the context of its policy initiatives to promote renewable energy to combat greenhouse gas emissions and climate change. The EU’s Member States are responsible for implementing EU policy: thus, the UK’s Renewables Obligation on electricity suppliers and its Renewable Transport Fuel Obligation and road‐fuel tax rebates are examined. It is unlikely that EU policy is in conflict with the WTO Agreement on Agriculture or that on Subsidies and Countervailing Measures, but its provisions on environmental sustainability criteria could be problematic. 相似文献
117.
Accounting for Negative,Zero and Positive Willingness to Pay for Landscape Change in a National Park
Nick Hanley Sergio Colombo Bengt Kriström Fiona Watson 《Journal of Agricultural Economics》2009,60(1):1-16
In contingent valuation, despite the fact that many externalities manifest themselves as costs to some and benefits to others, most studies restrict willingness to pay to being non‐negative. In this paper, we investigate the impact of allowing for negative, zero and positive preferences for prospective changes in woodland cover in two UK national parks, the Lake District and the Trossachs. An extended spike model is used to accomplish this. The policy implications of not allowing for negative values in terms of aggregate benefits are also investigated, by comparing the extended spike model with a simple spike making use of only zero and positive bids, and a model which considers positive bids only. We find that ignoring negative values over‐states the aggregate benefits of a woodland planting project by up to 44%. 相似文献
118.
Jon T. Biermacher B. Wade Brorsen Francis M. Epplin John B. Solie William R. Raun 《Agricultural Economics》2009,40(4):397-407
Plant-based precision nitrogen fertilizer application technologies have been developed as a way to predict and precisely meet nitrogen needs. Equipment necessary for precision application of nitrogen, based on sensing of growing wheat plants in late winter, is available commercially, but adoption has been slow. This article determines the expected profit from using a plant-sensing system to determine winter wheat nitrogen requirements. We find that plant-sensing systems have the potential to be more profitable than traditional nonprecise systems, but the existing system simulated was roughly breakeven with a traditional system. 相似文献
119.
We examine the relationship between participation in nonagricultural labor activities and farming production decisions, focusing on the use of inputs. Using longitudinal data for Vietnam from 1993 to 1998, we find that households engaged in nonagricultural labor spend significantly more on seeds, services, hired labor, and livestock inputs. This is consistent with the hypothesis that nonagricultural labor income relaxes credit constraints to farming. 相似文献
120.
Erik J. O’Donoghue Michael J. Roberts Nigel Key 《Journal of Agricultural Economics》2009,60(1):80-104
We estimate how much United States farms changed enterprise diversification in response to a marked increase in crop insurance coverage brought about by the 1994 Federal Crop Insurance Reform Act, which substantially increased insurance subsidies. The analysis exploits farm‐level panel census data to compare farm‐specific changes in enterprise diversification over time. By examining diversification decisions of the same farms over time, we control for time‐invariant unobserved individual heterogeneity. We then use pooled cross‐sectional data from the United States Department of Agriculture (USDA) Agricultural Resource Management Survey to estimate the relationship between farm diversification and average returns. We find that the insurance subsidies caused a modest increase in enterprise specialisation and production efficiency. Estimated efficiency gains are far less than the subsidies. 相似文献