首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
In many previous rice trade models, the commodity has been regarded as a homogeneous product. However, homogeneity is not an appropriate assumption, given the various types of rice that are traded and consumed. Parameters estimated from these models, therefore, do not reflect the real world market for rice and, hence, may mislead decision makers who use the results for policy evaluation purposes. This study uses an Armington approach to model the world rice trade as a differential good market and to derive trade elasticity parameters.  相似文献   

2.
3.
Theoretical models on group lending assume the formation of groups of homogenous risk types. Recent theoretical and empirical findings challenge this view arguing that when markets for insurance are missing, risk homogeneity may not hold any more and risk heterogeneity can be the optimal outcome. Using data from an MFI in Tigray (Ethiopia), this article examines the homogeneity hypothesis and reflects on implications for repayment. No evidence is found that supports risk homogeneity, even accounting for matching frictions. However, we also do not find an explicit link between the presence of risk heterogeneity and side-payments due to missing insurance as suggested in the literature. Instead, other trust-based social networks seem to underlie heterogeneity. Such social networks are often synchronized with credit groups and influence the probability of repayment under heterogeneity. The implication is that successful repayment rates in group lending need not arise only under risk homogeneity but can also arise under risk heterogeneity. Heterogeneity may also serve to bridge missing insurance markets in poor rural environments. MFIs therefore need to consider such local conditions when designing their lending schemes.  相似文献   

4.
This article provides a new interpretation of the scale effects in differential inverse demand systems. A scale curve is defined as a curve that shows how the expenditure share of a good or service changes as the consumption level changes. It is shown that Brown, Lee, and Seale's synthetic model has the same scale effects as do the Box–Cox scale curves. In this light, their model is not a mere composite but a model in its own right. An empirical illustration given for Japanese fresh food demand suggests that the underlying scale curves differ from both linear and loglinear forms.  相似文献   

5.
Government intervention changes the allocation of resources through effects on input and output prices. While explicit forms of intervention have been the subject of many studies, implicit forms of intervention have been given much less attention. The price and output policies pursued by public authorities systematically cross-subsidise from densely populated to sparsely populated areas. Thus, their effects are in the opposite direction from the effects of tariffs and quotas. Examination of the effects of one form of intervention in isolation overstates the net effects of that intervention. Effective rates of cross-subsidies must be taken into consideration when attempting to measure the impact of government intervention on resource allocation.  相似文献   

6.
In this paper is presented an analysis of the consumption patterns of beer, wine and spirits for Australia using data for the period 1955/56-1985/86. The validity of the demand theory hypotheses demand homogeneity and Slutsky symmetry has been tested using recently developed distribution? free procedures. The findings were that (i) beer and wine were necessities and spirits a strong luxury; (ii) beer and spirits are specific complements; and (iii) the homogeneity and symmetry hypotheses are acceptable. Preference for wine consumption seems to be independent of preference for beer and spirits.  相似文献   

7.
在研究旅游资源评价与古树名木资源评价现有成果的基础上,提出古树名木旅游资源评价及评价指标选取的基本原则。应用层次分析法(AHP),构建了古树名木旅游资源评价体系,并据此进行计算机处理、排序和检验,提出古树名木旅游资源等级指标,从而为科学评价古树名木旅游资源提供依据。  相似文献   

8.
新形势下如何做好地勘统计工作的探讨   总被引:2,自引:0,他引:2  
统计是管理的重要工具和手段。地勘单位属地化后,地质勘查统计无论在宏观方面还是在微观方面都面临着一些新的问题和困境,为适应的新形势、解决问题和走出困境,应从宏观管理、微观管理、统计报表、统计指标、贯彻统计法和提高统计人员工作能力等方面进一步改进和完善地质勘查统计工作。  相似文献   

9.
Pulpwood from Norway spruce (Picea abies (L.) Karst) traded domestically in Norway, imported to Norway, or exported from Norway is investigated with respect to commodity homogeneity and market integration. The prices imply that pulpwood from Norway spruce is a homogenous commodity, and the three price series are analyzed with respect to market integration. Using the cointegration estimator two cointegrating vectors are found within the system, and the weak Law of One Price can be imposed on domestic- and import prices. Imports are weakly exogenous to the two other variables, indicating that international pulpwood prices leads the domestic market.  相似文献   

10.
Market developments arising from closer vertical linkages in agri-food supply chains have given rise to a variety of issues. This paper outlines key issues and discusses possible responses by producers, their associations, and government. A vision of the future organization of agricultural production serves as a basis for discussion. The continued increase in contracting between producers and processors is accompanied by issues of contract transparency, terms, negotiation, and dispute settlement. Other ramifications include producer access to supply chains and the decline of spot markets. Furthermore, the development of agricultural biotechnology products may force a rethinking of the rationale for public investment in agricultural research and development. Evaluation of market power needs to account for efficiency gains from nonstandard forms of organization to achieve a balanced appraisal of the public interest. Agricultural economists are urged to evaluate new forms of firm and industry structure on the basis of how they work in practice rather than in comparison to an ideal form.  相似文献   

11.
The overall goal of our article is to better understand which matters for water savings, farmer income and poverty in China's irrigation systems: incentives to managers or participation of farmers. To pursue this goal, the article has three objectives. First, we track the evolution of water management reform, examining the practice of providing incentives to managers, and increasing the participation of farmers. Second, we identify the impact of water management reform on crop water use. Specifically, we want to measure whether or not incentives to managers and farmer participation in water management institutions affect the performance of the irrigation system. Because we also are interested in the potential results of water management reform, the article explores how changes in incentives and farmer participation affect farmer income and poverty. Based on a random sample of 51 villages and 189 farmers in four large irrigation districts in Ningxia and Henan provinces, both in China's Yellow River Basin, our results show that the two major forms of water management reform, water users' associations (WUAs) and contracting, have begun to systematically replace traditional forms of collective management. Our analysis demonstrates, however, that it is not the nominal implementation of the reform that matters, but rather it is the creation of new management institutions that offer water managers monetary incentives that lead to water savings. In contrast to the original design of China's reform policies, participation of farmers has not played a role in saving water. Importantly, given China's concerns about national food production and poverty alleviation, the reductions in water, at least in our sample sites, do not lead to reductions in income and do not increase the incidence of poverty.  相似文献   

12.
The purpose of this paper is twofold. Our first objective is to measure the level of technical efficiency of Québec dairy farms. Our second objective is to gauge the robustness of our results with respect to the selection of a functional form and of a distribution for the inefficiency index. We estimate efficiency frontiers for Cobb-Douglas (C-D), translogarithmic (TL) and generalized Leontief (GL) production functions with half-normal, truncated normal and exponential distributions. Our results, based on likelihood dominance criterion (LDC) indicate that the GL production technology dominates the other two functional forms, and this ranking is robust to changes in the distribution of the inefficiency index. Efficiency scores and ranks are highly correlated for all the functional forms and distributions. The differences in the mean levels of efficiency are statistically significant across functional forms and distributions, although the magnitude of the difference is minuscule. The very high mean level of efficiency and the low standard deviation confirms that Québec dairy farms are very homogenous in terms of getting the most from their inputs. This is not surprising, given that the sector has been very stable policywise and that it has been difficult for dairy farmers to expand. To augment the comparisons, results obtained from data envelopment analysis (DEA), are added to the analysis. In this case, the correlation coefficients between DEA and parametric specifications are found to be very low.  相似文献   

13.
Agronomic analyses of new technologies are often conducted under carefully controlled research station programs or trials managed by self‐selected farmers. Oftentimes, the technologies are then scaled up with minimal evaluation under real‐world conditions. Yet, the interim step between agronomic trials and large‐scale promotion is crucial to generate evidence on the social and economic impact of technologies that is both internally valid and generalizable. The article focuses on a participatory action research program in Malawi designed to test and identify scalable technology options to intensify the smallholder sector and contribute to poverty reduction and food and nutrition security. We examine the socioeconomic characteristics of farmers testing technologies and find evidence of systematic targeting of better‐endowed farmers. After controlling for observable differences using matching and a doubly robust estimator, we find evidence of early positive effects on maize yield and harvest value, although placebo tests suggest possible selection on unobservables. We note that attention should be given to program design and household characterization to better define and improve targeting criteria, technology selection, and external validity.  相似文献   

14.
The equilibrium allocation of owner operated and rental land in the agricultural sector is examined given risk averse agents, risky returns and asset price risk. The model is extended to account for disparities in bargaining power among landlords and farmers. In the absence of disparities, the competitive equilibrium allocation satisfies the general conditions for optimal risk sharing with an adjustment factor similar to the optimal hedge ratio. Differences in bargaining power result in deviations from the optimal risk sharing conditions. Numerical simulations of tenancy structure are conducted for a developed agricultural economy exposed to various forms of risk. Estimates of parameter values representing the riskiness of returns and asset prices in this study are based on vector auto regressive techniques. The simulations show that a substantial reduction of the rental ratio is obtained in a situation where farmers are equally or more risk averse than landlords. Consequently, the results indicate that the importance of the tenancy institution as a risk sharing mechanism is severely mitigated in the presence of asset price risk, risky returns, relatively risk averse farmers and disparities in bargaining power.  相似文献   

15.
The study considers the simultaneous estimation of share equations using cost and distance functions. Simultaneous rather than single system estimation utilizes full as opposed to limited information. Econometric results exploit the nonstationary nature of the data and that variables are cointegrated. Under cointegration all variables are endogenous and so it is not necessary to undertake the somewhat ad hoc exercise of choosing instruments to achieve parameter consistency. Johansen's maximum likelihood estimator is applied to data from Central Canada and Western Canada (1935–2006). Symmetry and homogeneity restrictions are not rejected for either region. Monotonicity held for all data points and concavity held at 92% of the data points. Long‐run constant returns and Hicks neutral technological change are rejected for both regions. Morishima elasticity estimates coming from the cost function in Western Canada indicate highly elastic long‐run substitution between the land/fertilizer input pair and mildly elastic long‐run substitution between land and both machinery and labor. In contrast, substitution for land and other inputs is inelastic for the land/machinery pair and the land/labor pair, with only the land/fertilizer pair being mildly elastic. The results indicate the limiting nature of land as a fundamental constraint on long‐term agricultural production is a real possibility in Central Canada because other inputs are inelastic, or at best only mildly elastic, substitutes for land. In Western Canada, fertilizer is the only factor that is highly substitutable for land and, therefore, could mitigate the limiting nature of land in that region. However, given that fertilizer applications are often considered to be environmentally unfriendly, the long‐run substitution of fertilizer for land as a fundamental mitigating factor to land scarcity in Western Canada is at a cost to the environment.  相似文献   

16.
The demand for meat has been estimated by many studies utilizing various data and estimation methods. In this study, we perform a meta‐analysis of the income elasticity of meat that involves regressing 3357 estimated income elasticities, collected from 393 studies, on variables that control for study characteristics. Across several meta‐regression specifications, we find significant differences in income elasticities tied to the type of meat being studied, as well as a few functional forms, data aggregations, publication characteristics, and locations of demand. However, many study characteristics do not significantly influence reported income elasticities. Less concern should be given to such characteristics when choosing an income elasticity from the literature.  相似文献   

17.
近年来,江苏省无锡市鹅湖镇通过实施标准化生产、品牌化建设、产业化发展,大力发展青鱼产业,在带动当地渔业增效、渔民增收方面发挥了突出的示范作用。本文介绍了甘露青鱼产业化发展概况,探讨了甘露青鱼产业化经营主要组织形式、标准化养殖及品牌建设情况,提出了强化合作经济组织辐射带动作用、积极拓展销售渠道、加快发展精深加工业等推进甘露青鱼产业化发展的建议。  相似文献   

18.
Lucerne (Medicago sativa L.) helps to prevent soil salinisation in the Western Australian Wheatbelt by reducing recharge to saline water tables. There is broad consensus, though, that it is not sufficiently profitable to motivate producers to plant it at the intensity at which considerable off‐site benefits would be conferred. This paper employs a multiple‐phase optimal control model to explore the value of this perennial pasture for the management of herbicide‐resistant annual ryegrass (Lolium rigidum Gaud.) in a crop–pasture rotation, given the difficulty of observing this value in practice. The availability of selective herbicides for efficient weed control is found to determine whether or not it is profitable to adopt lucerne pasture under optimal management. Herbicide resistance requires producers to employ costly, non‐selective treatments for in‐crop weed control. Thus, it motivates the adoption of perennial pasture in which cost‐effective forms of control can be implemented. Moreover, this result is robust to feasible changes in the current economic environment.  相似文献   

19.
Different forms of income diversification represent important strategies of farmers to either cope with the changing economic framework conditions or to valorise given territorial potentialities. Nevertheless, the decision to diversify economic activities on or off the farm will heavily depend on the agricultural business and household characteristics. Our study used a survey of 2154 farms from eleven European regions to identify distinct farm types in order to investigate differences regarding the willingness to diversify in the future. Two scenario situations with continuation (baseline) and without any market intervention (“No CAP”) were tested. A factor and cluster analysis depicted six farm types both previously described and novel. The typology proved validity across all case studies, whereas single types occurred more frequently under specific site conditions. The six farm types showed strong variations in the stated future diversification behaviour. Young farm households with organic production are most likely to diversify activities particularly on-farm, whereas farm types characterised by intensive livestock holding and also already diversified and part-time farm households are least likely to apply this strategy. Results have further shown that under hypothetical conditions of termination of economic support by the Common Agricultural Policy (CAP) an increasing share of farmers – throughout all types – would apply income diversification, mainly off-farm diversification, as a survival strategy.  相似文献   

20.
研究目的:在土地规模化和农业绿色发展的背景下,从全国和地区层面分析家庭农场土地经营规模对测土配方施肥技术应用的总体影响,发现其应用概率显著提高了具体土地规模区间。研究方法:运用IV方法对LPM和Probit模型进行估计。研究结果:(1)土地经营规模对农场应用测土配方施肥技术具有显著正向影响。土地经营规模每增加100亩,测土配方施肥技术应用概率平均提高2.10%。(2)政府倡导的适度规模经营与测土配方施肥技术的推广应用并不存在矛盾。相对于土地经营规模75亩以下的农场,当土地经营规模达到110亩后,农场应用测土配方施肥技术的概率会显著提高;110~225亩与225亩以上的农场应用测土配方施肥技术的概率无显著性差异。(3)相比于东北地区的样本农场,土地经营规模对测土配方施肥技术应用的正向影响效应在西部地区的样本农场中更明显。研究结论:促进土地向家庭农场等适度规模经营主体流转,注重不同地区测土配方施肥技术推广的差异性。  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