东北地区玉米生产及贸易概况

我国是生产玉米的大国,其产量约占世界的20%。东北地区是我国玉米的重要产区,是一条可与美国玉米带相媲美"黄金玉米带"。本文对东北地区玉米产量、种植面积及及进出口情况做了分析,得出东北地区玉米产量虽逐年上升,但所占比重增幅不大;种植面积增加,但单产变化不大,进出口量呈逆差状态的结论。     

基于市场均衡模型的中国玉米供需变化与趋势预测

当前国内外粮食供求形势在不断变化,为保障国家粮食安全,中国政府及相关部门提出研究构建国家粮食安全新战略体系。在此背景下,对中国玉米生产、消费、进出口的影响因素进行定量分析,通过构建市场均衡模型,对中国玉米供求平衡的变化与趋势进行预测分析。模型研究结果显示,对于玉米供给而言,到2025年中国玉米产量还有7.9%的上升空间,种植面积对于玉米价格的反应较为滞后,而农业补贴政策对于农民种植意愿的提高具有较为显著的效果;增强玉米生产科技要素的投入及提高抗击自然灾害的能力,有利于玉米单产水平的提高。对于玉米需求而言,到2025年中国玉米消费量将要增长38%,玉米饲用需求量和工业需求量呈刚性增长;由于玉米消费量增长速度高于生产量的增长,未来中国玉米产需缺口将会越来越大,玉米供求形势不容乐观。在此基础上,提出了立足国内生产、加大对农业四项补贴的投入力度、充分利用国际市场资源、科学调控玉米深加工等政策建议。     

澳大利亚的玉米深加工

玉米在澳大利亚是小作物。全澳的玉米种植面积为5万公顷,总产量20.2万吨,平均单产4.04吨/公顷(270公斤/亩),种植地区集中在昆士兰州的东南部和新南威尔士州的中北部。种植面积近年呈逐渐下降的趋势。尽管如此,澳玉米类型多样,品种齐全,农民同加工厂家签订产销合同,按照厂家要求选择品种类型,定质定量生产,以用于制造和生产不同的玉米食品和工业品。     

我国玉米产业技术进步的福利效应分析

在分别构建供给和需求模型对我国玉米生产消费状况进行分析的前提下,运用福利效应模型测算了技术进步对玉米生产者和消费者的福利效应,基本结论为:玉米具有较低的供给弹性和需求弹性,玉米技术进步的福利效应表现为消费者福利增加和生产者福利减少,但消费者福利的增加值大于生产者福利的减少值,使得整个社会的经济福利处于上升趋势。     

浅析我国谷子产业现状及对策分析

目前，我国谷子生产虽然在单产和总产居世界第一的地位，谷子的单产水平明显提高，但在生产发展中仍存在如种植面积显著下降导致总产量呈下降趋势，谷子生产的产业化程度较低等问题。文章就我国谷子生产发展现状进行了分析，并对其未来发展方向提出了相关建议。     

影响农户玉米种植规模的因素分析

党的十七届三中全会《决定》提出,要"确保国家粮食安全和主要农产品有效供给"。玉米作为一种重要的粮食作物,稳定生产对中国粮食安全具有重要意义。文章通过对当前及未来几年国内玉米供给及潜在需求形势的判断,认为中国玉米长期供不足需的局面不会改变、玉米供需缺口不容忽视。文章利用农户调查数据建立回归模型,对影响农户玉米种植规模的因素进行了定量分析,并在此基础上,就如何扩大玉米种植面积、提高农户玉米生产积极性、缓解未来玉米供需缺口提出了政策建议,包括:(1)玉米价格对农户玉米生产行为影响显著,国家应加大宏观调控力度,稳定玉米市场价格;(2)不同信贷来源农户的玉米生产行为不同,国家应创新支农信贷产品,保障生产资金供应;(3)农资价格并不必然对农户玉米生产行为产生负面影响,调控农资价格需与其他政策配合实施;(4)农户玉米生产中的风险规避因素明显,创新农业经营方式是保持粮食生产长期稳定的关键。     

玉米高产攻关栽培技术

第十管理区52作业站拥有耕地1181．6公顷,其中玉米面积达500余公顷,占耕地面积的42％,平均单产8．5吨,公顷产值7750元,公顷效益3800余元,是广大职工增收的一个主要作物之一,越来越受到广大职工的重视,其生产技术措施也在不断改进,今年我分公司玉米种植面积都很大,但产量不一,除去自然因素外,就是生产管理方面,下面就介绍一下我站玉米高产经,与大家共勉。     

我国烤烟的供给反应分析

本文利用Nerlove模型分析我国烤烟的供给反应。结果表明:当期烤烟价格对烤烟的种植面积有显著的正向影响,前期粮食价格对烤烟的种植面积有显著的负向影响。进一步分析可知,粮食价格对烟农的种植决策有着不可忽视的影响,影响程度甚至超过了烤烟自身的价格。     

水稻插秧机技术的研究

一、目前我国水稻插秧机械技术的现状 水稻是我国种植面积最大、单产最高、总产最多的主要粮食作物，其常年种植面积和总产约占我国粮食作物的28％和40％，种植方式主要为传统的人工插秧：虽然我国在20世纪60年代已开始水稻种植机械化研究，对插秧机关键部件的设计与研究有所突破，但使用成本高，可操作性差，     

浅谈玉米机械收获技术的发展前景

玉米是世界上种植最广泛的谷类作物之一，也是我国第三大种植作物，种植面积大，且分布广泛。近年来，围绕玉米生产关键环节——玉米收获机械化，全国各地都不断探索，并取得了较大突破。现阶段，我国玉米收获机的发展仍处于开发期，这个市场还需要培养和引导。这个热潮中包含了许多小麦收获机热的“余热”，而不是真正的“自热”。玉米收获机械的发展需要不断完善、提高，还需要加大推广宣传力度。     

现代农业中种植业技术进步的随机前沿分析

基于随机前沿的分析方法,利用国内11个省市9年的面板数据,对现代农业中小麦、粳稻和玉米的生产函数和技术效率进行了分析,研究结果表明,种植业生产中,技术进步是提高技术效率的主要影响因素,样本地区的小麦、粳稻和玉米的生产通过技术进步来提高产量还有一定的空间。     

国际化进程中我国农作物种植效率研究

本文选取大豆、梗稻、玉米三种农作物,使用1994—2006年间若干代表年份的数据,通过DEA方法计算了我国农业国际化进程中农作物的种植效率,并在此基础上研究农作物种植效率与国际化开放程度之间的关系。研究结果表明,在我国加入WTO之后,三种农作物的技术效率整体上呈现震荡上升的趋势;实证检验发现,农作物开放程度的提升确实会带来种植效率的显著提升,尤其是对于具有出口优势的玉米,开放程度对种植效率的影响更为显著。     

Examining crop price effects on production decision and resource allocation: an ex-ante approach

This article examines the output price effects on the US crop production, employing an ex-ante approach to the differential systems of input demand and output supply. The estimation results of the differential input demand show that the expansion of crop production leads to an increase in acreage (i.e. extensive margin) and a proportional rise in input usage improving yield per acre (i.e. intensive margin). The substitutable relationship between fertilizer and land supports that crop producers have an option to choose either intensive or extensive margin in response to changes in their relative prices. In addition, the estimation results of the differential output supply highlight that the composition of crop supply can be altered by changes in ex-ante crop prices. The estimation results suggest that crop producers substitute corn supply for the supply of cotton, wheat and soybeans or vice versa. Based on the estimated elasticities, the decompositions of profit-maximizing input demand are conducted, which reveals that a change in ex-ante crop prices is associated closely with resource reallocation.     

Food Protection for Sale*

This article tests the Protection for Sale (PFS) model using detailed data from US food‐processing industries under alternative import‐demand specifications. All empirical results support the PFS model predictions and previous empirical work qualitatively. However, a surprising result is that we obtain weights between 2.6 and 3.6 for domestic welfare using import slopes or elasticities derived from domestic demand and supply functions. In contrast, results based on directly specified import demands (including the Armington model) yield the usual, unrealistically large estimates for the domestic welfare weight. We contend that this empirical paradox arises mainly because the explanatory variables tend to be extremely large for industries with low import ratios and/or low import elasticities (or slopes) resulting from relatively volatile import prices. The results with derived import parameters point to a much stronger role of campaign contributions within the PFS model than previously found.     

新疆哈密瓜标准化生产模式研究

根据新疆哈密瓜标准化生产基地建设情况,特别是新疆不同地区的产业发展规划及区域发展特点,总结了目前新疆哈密瓜标准化生产基地的三种模式,并对这三种模式进行进一步分析及评价,为以后新疆哈密瓜标准化生产基地的发展起到一定的推动作用。     

Taxation and top incomes in Canada

We estimate the elasticity of reported income with respect to tax rates for high earners using sub‐national variation across Canadian provinces. We argue this allows for better identification of tax elasticities than the existing literature. We find that elasticities of reported income at the provincial level are large for incomes in the top 1%, but small for lower earners. There are strong indications that the response happens both through earned and capital income. While our estimated elasticities are large, changes in tax rates cannot explain much of the overall long‐run trend of higher income concentration in Canada.     

Demand elasticities for food products in Brazil: a two-stage budgeting system

The object of this article is to estimate demand elasticities for a basket of staple food important for providing the caloric needs of Brazilian households. These elasticities are useful in the measurement of the impact of structural reforms on poverty. A two-stage demand system was constructed, based on data from Household Expenditure Surveys (POF) produced by IBGE (The Brazilian Bureau of Statistics) in 1987/88 and 1995/96. We have used panel data to estimate the model, and have calculated income, own-price, and cross-price elasticities for eight groups of goods and services and, in the second stage, for 11 sub groups of staple food products. We estimated those elasticities for the whole sample of consumers and for two income groups.     

城乡结合部区域农户土地利用行为差异及其政策启示——以沈阳市苏家屯区238户农户调查为例

城乡结合部是中国工业化、城市化进程中形成的独特区域,该区域土地利用问题敏感、复杂且意义重大。从农户土地利用行为角度出发,通过构建工业化、城市化进程中农户土地利用行为差异形成机理分析框架,采用方差分析、统计分析的方法,以辽宁省沈阳市苏家屯区238户农户的调查问卷为基础,对城乡结合部农户土地利用行为变化规律进行研究。结果表明：该区域农户土地利用行为在空间分布上呈现＂反图能圈＂式的种植业布局模式,具有明显的＂非农化＂与＂非粮化＂的特征。其中近郊区农户以＂粮食需求＂为主,主要种植玉米,土地利用程度低,土地投入强度小。远郊区农户以＂粮食需求和利润需求协调＂为主,兼种大田作物和陆地蔬菜,农户土地利用程度较高,土地投入强度较大。纯农村农户以＂利润需求＂为主,主要种植大棚蔬菜和陆地蔬菜,土地利用程度最高,土地投入强度最大。在结论的基础上,提出应该从完善农村社会保障体系、健全农地流转机制、加大农业科技投入力度、优化农业产业的合理布局等方面引导农户合理利用土地资源,实现土地利用效率的提高和土地资源的可持续利用。     

Margins,Concentration and Oligopolistic Interdependence*

In this paper we examine the relationship between margins, elasticities of demand and the Hirschman-Herfindahl index of concentration for Australian manufacturing. Our main aim is to estimate the degree of collusion in various manufacturing sectors in the years 1968-69, 1972-73 and 1977-78. There appear to be marked differences in the apparent degree of collusion between industries. It is argued that once sub-optimization is allowed the Cowling-Waterson model will yield biased estimates of the degree of collusion.     

Conditional and unconditional food demand elasticities in a dynamic multistage demand system

This paper estimates conditional and unconditional demand elasticities in a three stage analysis of consumer demand for food and non-food items in Greece. A dynamic version of the AIDS model is specified and estimated, and full system misspecification tests applied. Correction formulas for price and expenditure elasticities are used to calculate unconditional elasticities from conditional demand sub-systems. All food items rank as price inelastic. Deviations between the calculated conditional and unconditional price and expenditure elasticities are found to be significant, demonstrating the importance of correcting conditional elasticities before they can be used for policy purposes or welfare analyses.