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1.
On-farm experiments to study soil fertility depletion—one of the biophysical factors limiting crop production—were conducted in six villages of central Myanmar during 1997 to 1999. Systematic socioeconomic surveys and analysis of socioeconomic and crop production factors aided the selection of farmers.

Topsoil mineral nitrogen content at the start of the cropping season was high (10–25 mg N kg?1). Available phosphorous was around the threshold level for most crops, but exchangeable potassium was low. The predominant continuous cropping system of sole groundnut was on average positive for P (0.24 kg ha?1 y?1) and K (7.05 kg ha?1 y?1) and negative for N (?32.4 kg ha?1 y?1). A negative balance for N in the groundnut/pigeonpea (?58 kg ha?1 y?1) and mung bean/pigeonpea (?56 kg ha?1 y?1) intercropping systems was noted. The nutrient balances were positive in early sesame—late sesame (29 kg N ha?1 y?1, 8 kg P ha?1 y?1, 33 kg K ha?1 y?1) and early sesame/pigeonpea (8 kg N ha?1 y?1, 15 kg P h?1 y?1, 44 kg K ha?1 y?1) production systems while sole sorghum system resulted in positive balance for N (23.8 kg ha?1 y?1) and negative balance for K (?3.8 kg ha?1 y?1).  相似文献   

2.
Cross-sectional data are used to estimate a three-equation generalised addilog demand system (GADS); two equations are used to express the demand for milk by method of sale and a residual equation is used to close the system. It is shown that, as the average budget share of the residual equation approaches unity, the GADS equations for the incomplete system are approximately equivalent to double logarithmic equations. It is found that aggregate milk demand is relatively insensitive to both price and income, but the degree of substitution between delivered and non-delivered milk is both large and highly significant. A new test for influential data in the system context is developed and it suggests that the reported results are robust to variations in the sample space.  相似文献   

3.
An earlier article *was concerned with the assessment of the net contribution (if any) made to the balance of payments by a marginal expansion of U.K. agricultural output. Such evidence as there is suggests that an increase in U.K. agricultural output would make a positive contribution to the Balance of Payments, though this contribution might be only about one half the value of net import saving. In addition it is necessary to compare agricultural expansion with other measures which are intended to make a positive contribution to the Balance of Payments. The purpose of this article is to re-examine the theoretical ideas behind the argument for using home resources to save imports. This argument was first put forward in the early 1950's and was concerned primarily with agricultural import saving and export promotion as alternative methods of alleviating the contemporary Balance of Payments problem. The argument has become relevant once again with the current proposal for further agricultural expansion to aid the U.K. Balance of Payments. A new method of presentation is employed which it is hoped adds clarity to the exposition. In addition it is suggested that the theory behind this argument is inadequate from the point of view of its application to agricultural import saving: agricultural import substitution gives a country only the potential to turn the terms of trade in its favour. A necessary second stage in the process—the realisation of this potential—seems to have been overlooked by previous writers. The theory is also considered under an assumption of flexible exchange rates, and it is argued that the use of the exchange rate as a balancing mechanism results in a failure to exploit any inelasticity of demand for a country's exports  相似文献   

4.
The Australian demand for domestically-produced sawn timber is investigated by considering its major use — as an input into residential construction. Using a cost function approach, a system of equations is derived expressing quantities demanded in terms of relative prices. Cross-price elasticities are estimated and the falling input-output ratio of timber in residential construction is analysed by decomposing the change in this ratio into price, outputs and taste/technology effects. A major finding is that, while substitution of timber for other inputs has been encouraged through relative price movements, this effect has been more than offset by taste and technology trends away from timber usage.  相似文献   

5.
Studies of the ease of substitution between inputs in production have generally been carried out within a production framework of an explicit functional form. In this study, a somewhat different approach is followed. A model of derived demand for primary factors of production, land, labour and capital is formulated to enable inferences to be made about the characteristics of the unspecified production function. The model is used to obtain estimates of the pairwise Allen-Uzawa substitution elasticities which are secondary parameters of the underlying production function. The reported FIML estimates from aggregate time series data for the period 1920/21 to 1969/70 indicate very low and marginally different substitution elasticities between different pairs of factors, suggesting that both the Cobb-Douglas and CES production function specifications for the Australian agricultural sector are inappropriate.  相似文献   

6.
A method for calibrating agricultural production models is presented. The data requirements are those for a linear programming model with the addition of elasticities of substitution. Using these data, production models with a CES production function can be simply and automatically calibrated using small computers. The resulting models are shown to satisfy the standard microeconomic conditions. When used for analysis of policy changes, the CES models are able to respond smoothly to changes in prices or constraints. Prior estimates of elasticities of substitution, supply or demand can be incorporated in the models.  相似文献   

7.
鉴于中国原木进口需求弹性的参数值信息有限,利用月度时间序列数据构建中国原木进口需求函数,在Johansen协整框架下展开计量分析。向量误差修正模型的估计结果显示:中国原木的进口需求对所有变量都是缺乏弹性的,且在1%的统计水平上显著;中国国内经济产出和实际进口价格的弹性分别为0.86(±0.05)和-0.68(±0.15),短期对长期均衡的偏离的调整系数为0.61。基于估计参数的预测结果显示,受经济新常态的影响,2020年中国原木进口量约为5067万m3~6464万m3,并呈现平稳增长的态势。  相似文献   

8.
9.
A generalized version of a well-known statistical result is used to suggest an alternative strategy for estimating nested constant elasticity of substitution preferences for recreation demand. Parameter and welfare estimates from nested constant elasticity of substitution count data demand system models are presented and compared to estimates from the multinomial approaches developed previously. A significant advantage of the count data estimation strategy over the multinomial-based approaches is that the analyst avoids the difficulties associated with choice occasion specification and interpretation.  相似文献   

10.
A relative increase in demand for one type of beef can have one of two potentially countervailing effects: it can cause substitution of one type for another and/or it might expand overall demand. The results of a random parameters logit analysis indicate that regardless of whether USDA Choice or upgraded steak demand increases, the expansion effect dominates the substitution effect. We also show that, for our sample of consumers, the introduction of a new "natural" steak causes a greater reduction in market share for USDA Choice beef than ungraded beef. Despite this result, however, overall steak demand increases.  相似文献   

11.
The extent to which wools with different fibre characteristics can be substituted in textile production and consumption holds implications for Australia's international and domestic marketing policies. An analysis of price-induced substitution between Australian wools of different fibre diameters was conducted. Fibre diameter was used to parameterise cross-price relationships in order to estimate a system of demand equations for wools by diameter class. The results indicate that direct substitution takes place within a very limited range of fibre diameters. The use of product characteristics to parameterise price relationships may be extended to other graded commodities.  相似文献   

12.
Elasticities of substitution, often called Armington elasticities, reflect incomplete substitutability because of perceived product characteristics. This study divides the determinants of the Japanese demand for beef imports into two factors: (i) substitution elasticity and (ii) country-of-origin bias, and demonstrate how these measurements are associated with trade policy and food scare events. The Japanese beef industry serves as a case study to evaluate the multifold impact of import liberalisation and a series of bovine spongiform encephalopathy (BSE) outbreaks. A time-varying parameter model is used to shed light on the dynamic effects of the import liberalisation and BSE outbreaks on the measurements. The estimation results reveal that the estimated substitutability and country-of-origin bias are very sensitive to the BSE cases, but not to the process of trade liberalisation. The results also confirm that as a result of the BSE outbreaks, the major factor of the Japanese demand for beef imports has changed from relative prices to the country-of-origin effect, thereby emphasising the importance of a traceability system and promotional activities, which would help in the formation of the country-of-origin effect.  相似文献   

13.
This paper examines the possibilities for interfuel substitution in Australia in view of the need to shift towards a cleaner mix of fuels and technologies to meet future energy demand and environmental goals. The translog cost function is estimated for the aggregate economy, the manufacturing sector and its subsectors, and the electricity generation subsector. The advantages of this work over previous literature relating to the Australian case are that it uses relatively recent data, focuses on energy‐intensive subsectors and estimates the Morishima elasticities of substitution. The empirical evidence shown herein indicates weak‐form substitutability between different energy types, and higher possibilities for substitution at lower levels of aggregation, compared with the aggregate economy. For the electricity generation subsector, which is at the centre of the CO2 emissions problem in Australia, significant but weak substitutability exists between coal and gas when the price of coal changes. A higher substitution possibility exists between coal and oil in this subsector. The evidence for the own‐ and cross‐price elasticities, together with the results for fuel efficiencies, indicates that a large increase in relative prices could be justified to further stimulate the market for low‐emission technologies.  相似文献   

14.
This article provides a method where pre-tests for international market integration are used to identify market structures before estimating demand systems. The method is applied to the analysis of the European herring market. A Vector Auto Regressive model in Error Correction form is used to identify co-integration vectors between price series and, based on this, to test for the Law of One Price. The Law of One Price is in force between the landing markets for herring in the two largest global supplier countries, Norway and Denmark. Therefore, an inverse demand function is estimated for the combined Norwegian and Danish market. The results are used in the interpretation of the significant increase in the prices of herring on the Danish ex-vessel market in 2001, given the stability of the Danish market. The implication is that even though Denmark did not export to the main Norwegian export markets in the former Soviet Union and Eastern Europe, the Danish landing price is influenced by the situation there.  相似文献   

15.
Inverse demand systems explain price variations as functions of quantity variations. This article presents a dynamic inverse almost ideal demand system (AIDS) model based on recent developments on cointegration techniques and error correction model. The case of fish landed at Greek seaports appears to suit this model well. The results indicate that the underlying distance function is homothetic whereas the own-quantity flexibilities suggest that the responses of price to own-quantity changes are inelastic. Finally, the results of cross-quantity uncompensated flexibilities suggest that the substitution possibilities among fish grades are rather limited. The Allais interaction intensities verified the substitutability among fish grades as well.  相似文献   

16.
以猕猴桃果酒为原料,探讨了不同化学降酸物质对果酒降酸的影响。通过采用单因素实验和正交实验确定了降酸效果最优的化学降酸法:以CaCO3、K2CO3、酒石酸钾联合降酸效果最佳,3.0 g/L的CaCO3,1.2 g/L的K2CO3和4.0 g/L的酒石酸钾可使猕猴桃果酒的酸度从13.85 g/L降低到7.31 g/L,降酸率达到47.22%。此法不仅能降低果酒的酸度,而且还能保持其良好的风味口感。该实验结果可以为生产优质猕猴桃果酒提供一定依据。  相似文献   

17.
A computable general equilibrium model was used to assess the impacts of global climate change on Canadian Agriculture. The assumption of ceteris paribus was relaxed. The results indicated that many supply and demand factors have potentially larger impacts on the Canadian and world economies over the next 5 decades than climate change. The distribution of regional impacts varied substantially. Such information is valuable for the agricultural sector and policymakers trying to allocate limited resources .  相似文献   

18.
基于双变量Probit模型从需求和供给两个角度对浙江省丽水市公益林补偿收益权质押贷款试点地区255个林农的贷款可得性、内在联系及影响因素进行研究。结果表明:60.39%的林农对公益林补偿收益权质押贷款有需求,11.76%的林农成功获得贷款;丽水试验区公益林补偿收益权质押贷款存在供给范围较窄、公益林小户和大额资金需求得不到有效满足等问题;户主受教育程度、家庭人口负担、公益林面积、贷款期限是影响林农收益权质押贷款需求决策的因素;在需求约束下,年龄小、受教育程度高、公益林面积大、优质存量客户的贷款可得性更高,并且公益林补偿收益权质押贷款的可得性更依赖于林农家庭经济状况。  相似文献   

19.
通过问卷调查了解福建省永安市、尤溪县、连城县、永泰县这4个重点林区林农生产类公共信息服务需求情况。在此基础上,以林农个体特征、诱导因素、生产类公共信息服务获取渠道、信息质量、林农付费意愿、林农对信息服务人员的认可等作为林农生产类公共信息服务需求的预期影响因素,利用多元线性回归分别对林农生产类公共信息服务需求影响因素进行了实证分析。结果表明:林农需求的主要影响因素为林农的健康状况、家庭林业年收入、林农付费意愿、对服务人员的认可和信息获取渠道数。因此,提出拓宽林农公共信息服务获取渠道;从数量和质量上提高林业公共信息服务水平;注重信息服务人员与林农需求之间的对接以及提高林农对信息的认知等建议。  相似文献   

20.
基于浙江省丽水市调查数据,采用Logistic模型和Tobit模型,实证分析家庭禀赋对农户公益林收益权质押贷款需求及其额度的影响。结果表明:大多数农户对贷款有需求;农户存在以中长期生产性借贷为主的潜在贷款需求特征;家庭的人力资本、社会资本、自然资本、经济资本均是影响农户公益林收益权质押贷款需求的因素;公益林大户相对于公益林小户贷款需求意向更为强烈;家中发生大事、政府贴息、贷款期限、林权抵押贷款经历均对农户公益林收益权质押贷款需求和需求额度具有显著正向影响;贷款用途限制对农户公益林收益权质押贷款需求和需求额度具有显著负向影响。因此,政府机构应鼓励各地加大贴息力度,为农户提供融资增信,银行业金融机构应合理确定贷款期限,农户应注重自身资源禀赋的积累和利用,政府及各地基层、相关金融机构应加大金融宣传力度。  相似文献   

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