全文获取类型
收费全文 | 5824篇 |
免费 | 202篇 |
国内免费 | 67篇 |
专业分类
财政金融 | 257篇 |
工业经济 | 538篇 |
计划管理 | 1086篇 |
经济学 | 1003篇 |
综合类 | 544篇 |
运输经济 | 29篇 |
旅游经济 | 30篇 |
贸易经济 | 652篇 |
农业经济 | 1286篇 |
经济概况 | 668篇 |
出版年
2024年 | 23篇 |
2023年 | 80篇 |
2022年 | 96篇 |
2021年 | 158篇 |
2020年 | 246篇 |
2019年 | 153篇 |
2018年 | 131篇 |
2017年 | 175篇 |
2016年 | 174篇 |
2015年 | 170篇 |
2014年 | 387篇 |
2013年 | 430篇 |
2012年 | 448篇 |
2011年 | 526篇 |
2010年 | 392篇 |
2009年 | 358篇 |
2008年 | 386篇 |
2007年 | 344篇 |
2006年 | 337篇 |
2005年 | 251篇 |
2004年 | 161篇 |
2003年 | 127篇 |
2002年 | 96篇 |
2001年 | 116篇 |
2000年 | 91篇 |
1999年 | 58篇 |
1998年 | 37篇 |
1997年 | 23篇 |
1996年 | 16篇 |
1995年 | 10篇 |
1994年 | 19篇 |
1993年 | 12篇 |
1992年 | 8篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 13篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有6093条查询结果,搜索用时 15 毫秒
41.
《Food Policy》2019
In recent decades, agricultural production in the U.S. has continued to shift to large-scale operations, raising concerns about the economic viability of small and midsized farms. To understand whether economies of size provided an incentive for the consolidation of production, the study estimates the total factor productivity (TFP) of five size classes of grain-producing farms in the U.S. Heartland (Corn Belt) region. Using quinquennial Agricultural Census data from 1982 to 2012 the study also compares TFP growth rates across farm sizes to gain insight into whether observed productivity differences are likely to persist. The finding of a strong positive relationship between farm size and TFP suggests that consolidation of production has contributed to recent aggregate productivity growth in the crop sector. The study estimates the extent to which sectoral productivity growth can be attributed to structural change versus other factors including technological change. The study also explores some tradeoffs associated with policies that raise the productivity of small versus large farms. 相似文献
42.
《Food Policy》2019
This research studies the determinants of pig farmers’ participation in farmers’ cooperatives and the effects of farmers’ cooperatives on pig farmers’ behaviors in adopting safe production practices using data from a household survey of 540 cooperative farmers and 270 non-cooperative farmers from four main pig production provinces in China. The propensity score matching (PSM) method was adopted to deal with possible self-selection bias associated with farmers’ participation in farmers’ cooperatives due to observables, which is further supplemented by a sensitivity analysis to assess the degree to which the PSM results are robust to the presence of unobservables. The PSM results show that the cooperative membership has significant and positive influence on farmers’ propensity to adopt safe production practices and the effects are heterogeneous across a number of key cooperative, farm and household attributes. Specifically, the membership effects tend to be bigger for cooperatives led by Investor-owned firms (IOFs) and farms of small production scale. And the effects tend to be greater for households (1) of medium and high level of education, (2) of less than 10 years of pig production experience, (3) of no off-farm job experience, and (4) that are specialized in pig production. The sensitivity analysis further increases our confidence in the results for the feed use and the breed use, however, the results for vaccination, drug use and waste disposable are more sensitive to the influence of unobservables, therefore should be interpreted with caution. 相似文献
43.
《Food Policy》2019
This article tests the hypotheses of convergence to a single level of total factor productivity (TFP), and a steady state of TFP growth rate in China’s agricultural sector. Based on multilateral TFP estimates we found that China’s agricultural sector has rebounded in recent years from a slower TFP growth in the 2005–2007 period. While convergence test results confirm a “catch-up” effect that provinces with lower TFP levels tend to grow faster than others, estimated rates of β convergence are conditional on how we capture the heterogeneity effect across regions. The rates of β convergence range from 0.016 to 0.039 under different model specifications. Estimates show that higher growth rates of educational attainment, R&D, and intermediate goods density (per unit of labor) can enhance TFP growth. Unfortunately, there is no evidence of an overall σ convergence, indicating that TFP levels are not converging except in the South region. It implies that to catch up with leading provinces, it would require extra efforts for those lagging behind by increasing their region-specific research investment, promoting rural educational attainment, and enhancing embodied technical change. 相似文献
44.
《Food Policy》2019
This paper examines how smallholders living in regions where a drought is forecasted adapt their farm practices in response to receiving seasonal forecast information. The article draws on a unique longitudinal dataset in Zambia, which collected information from farm households before and after a significant drought caused by the 2015/2016 El-Niño Southern Oscillation. It finds that farmers residing in areas forecasted to be drought-affected and receiving seasonal forecast information are significantly more likely to integrate drought tolerant crops into their cropping systems compared to similar households not receiving this information. Moreover, the probability that a farmer implements these adaptive farm management strategies in response to seasonal forecast information is found to increase substantially as the number of private grain buyers in the farmers’ village increases. This suggests that climate change adaptation and resilience strategies that integrate the generation and dissemination of weather information with agricultural market development can achieve greater impact on farmers’ adaptive responses than approaches that treat these activities in isolation. 相似文献
45.
阐述了油气开采用机械类产品的分类和特点、标准的编制原则和对标准内容的要求,介绍了新疆油田在审查机械产品标准中的做法,讨论了对产品标准编制和审查中涉及的常见问题,对机械产品标准的制修订和审查工作提出了一些建议。 相似文献
46.
《Food Policy》2014
The paper analyses farm worker welfare on three different types of farms in Kenya producing vegetables for export. The three types of farms differ by certification to international production standards as well as by size. A multidimensional approach measures welfare using human capital, income, physical and mental health, and life satisfaction. The findings suggest that GlobalGAP certification has a positive impact on worker welfare as farm workers are given more training. Workers on large certified farms earn more than those on small farms but also show more health problems. Certification on small farms is associated with higher satisfaction of workers with their life compared to workers on non-certified small farms. From a development policy perspective this paper does not support a clear cut policy on which types of farm to support as overall benefits of a support strategy will depend of the number of beneficiaries reached through the different farm types. 相似文献
47.
《Food Policy》2014
This article uses nationally representative household-level panel data from Malawi to estimate how rural population density impacts agricultural intensification and household well-being. We find that areas of higher population density are associated with smaller farm sizes, lower real agricultural wage rates, and higher real maize prices. Any input intensification that occurs seems to be going to increasing maize yields, as we find no evidence that increases in population density enable farmers to increase gross value of crop output per hectare. We also find evidence that households in more densely populated areas increasingly rely on off-farm income to earn a living, but there appears to be a rural population density threshold beyond which households can no longer increase off-farm income per capita. 相似文献
48.
《Food Policy》2014
Over the last decade, Zambia has witnessed a rapid increase in the number of medium-scale “emergent farms” cultivating 5–20 ha of land. This study analyzes the factors underpinning this growth. We find that the growth of emergent farmers in Zambia is primarily attributable to land acquisition by salaried urbanites and by relatively privileged rural individuals. We found little evidence to support the hypothesis that the rise of emergent farmers primarily represents a process of successful accumulation by farmers who began farming with less than 5 ha of land, a situation faced by more than 95% of farming households. We argue that these outcomes are the result of Zambia’s land administration and agricultural spending policies. Rising concentration of landholdings in Zambia raises serious questions about the potential of current agricultural growth to act as a vehicle for broad based economic growth and poverty reduction. 相似文献
49.
《Food Policy》2014
Evidence assembled in this special issue of Food Policy shows that rising rural population densities in parts of Africa are profoundly affecting farming systems and the region’s economies in ways that are underappreciated in current discourse on African development issues. This study synthesizes how people, markets and governments are responding to rising land pressures in Africa, drawing on key findings from the various contributions in this special issue. The papers herein revisit the issue of Boserupian agricultural intensification as an important response to land constraints, but they also go further than Boserup and her followers to explore broader responses to land constraints, including non-farm diversification, migration, and reduced fertility rates. Agricultural and rural development strategies in the region will need to more fully anticipate the implications of Africa’s rapidly changing land and demographic situation, and the immense challenges that mounting land pressures pose in the context of current evidence of unsustainable agricultural intensification, a rapidly rising labor force associated with the region’s current demographic conditions, and limited nonfarm job creation. These challenges are manageable but will require explicit policy actions to address the unique development challenges in densely populated rural areas. 相似文献
50.
《Food Policy》2016
We examine the effect of globalization, in its economic and social dimensions, on obesity and caloric intake, namely the so –called ‘globesity’ hypothesis. Our results suggest a robust association between globalization and both obesity and caloric intake. A one standard deviation increase in globalization is associated with a 23.8 percent increase in obese population and a 4.3 percent rise in calorie intake. The effect remains statistically significant even after using an instrumental variable strategy to correct for some possible reverse causality and ommited variable bias, a lagged structure, and corrections for panel standard errors. However, we find that the primary driver (of the ‘globesity’ phenomenon) is the ‘social’ rather than the ‘economic’ dimension of globalization, and specifically the effect of changes in ‘information flows’ and ‘social proximity’ on obesity. A one standard deviation increase in social globalization increased the percentage of obese population by 13.7 percent. 相似文献