国内外玉米价格传导关系影响研究基于收购政策市场化改革背景

[目的]玉米在国家粮食安全中占有重要地位,是国内外市场联系最为紧密的大宗农产品之一。文章旨在探讨收购政策市场化改革前后,国内外玉米价格传导关系是否发生变化,为政府推进玉米供给侧改革提供理论依据。[方法]该文选取2009—2018年国内外玉米价格周度数据,利用向量误差修正模型和门限向量误差修正模型分别对收购政策市场化改革前后国内外玉米市场间价格传导关系进行实证分析。[结果]长期内,国内外玉米价格存在长期稳定的均衡关系,国际玉米价格对国内玉米价格具有持续稳定的正向传导关系;短期内,收购政策市场化改革前,国内外玉米价格间存在线性调整关系,具体表现为国际玉米价格向国内玉米价格单向传导关系;而收购政策市场化改革后,国内外玉米价格短期非均衡误差调整动态存在门限非对称调整关系,且改革后未来国内玉米价格受到当期国内玉米价格影响较大。[结论]这些结论对推进玉米供给侧改革,维护国内玉米市场的健康有序发展有一定的参考作用。     

Vertical price transmission in timber and lumber markets

Timber and lumber markets are linked and integrated through prices at several stages along timber supply chain. In this study, the degree of vertical integration and the presence of asymmetric price transmission are investigated for sawtimber and lumber products in the southern and western United States. The data utilized are quarterly stumpage price, delivered timber price, and lumber price of softwood between 1977 and 2011. Linear and threshold cointegration models are used for long-term price analyses, and symmetric and asymmetric error correction models are used for short-term price analyses. The integration in the early stage (i.e., stumpage/delivered timber price pair) is found to be stronger than that in the latter stage (i.e., delivered/lumber price pair). The South shows slightly stronger market cointegration than the West. Asymmetric price transmission is found along the timber supply chain. In the long term, prices are more responsive when the price margin is increased than decreased.     

Stumpage prices in Sweden 1909–2012: Testing for non-stationarity

The price of timber stumpage is one of the few natural-resource rents that can be directly observed as a market price. Rules for optimal timber harvesting under uncertainty have been found to depend on whether the timber rent price is non-stationary or stationary. In this study we extend previous research by Hultkrantz (1995) that tested for unit-root with an exogenous break point in Swedish stumpage prices from 1909 to 1990, employing data up to 2012, hence for 104 years, and unit-root tests with endogenously selected break points. We find support for a structural level break at the end of WW2 and that non-stationarity can be rejected. We show that this is a robust conclusion. There is thus no sign of a new break in the extended recent time period and no signal of a secular increase of timber resource scarcity.     

Canadian Hog Supply Response: A Provincial Level Analysis

Canada's hog sector has faced two decades of tumultuous growth, yet there are no recent estimates of supply response. This study uses state‐space methods to account for a multiplicity of autonomous structural changes impacting the sector and determines if the fundamental relationship between supply response and hog prices has changed from previous estimates. The results are consistent with prior research but offer the reader previously unavailable estimates of supply response with respect to feed prices and the variability of hog and feed prices. Feed price elasticities are somewhat larger than hog price elasticities. The effects of price risk for supply response appear quite muted but the impacts of feed price risk are greater than for hog price risk.     

Application of the generalized Faustmann model to uneven-aged forest management

In this paper, a generalized Faustmann model is developed for uneven-aged management to allow the number of years and the level of residual growing stock to vary from one cutting cycle to the next. Comparative static analyses are conducted to determine the effect of changes in interest rate, stumpage price of the trees selected for harvest, the stumpage value of the residual growing stock, and the future land value on the decision variables. The model is then applied to study the uneven-aged management of a loblolly-shortleaf pine stand in south central U.S. to determine the length of the cutting cycle and the level of residual growing stock for the first cutting cycle as well as for a case involving four cutting cycles. Sensitivity analyses reveal that for the uneven-aged loblolly-shortleaf pine stand both the length of the cutting cycle and the level of the residual growing stock are very sensitive to changes in land value in the future, in the stumpage prices of trees selected for harvest, in the stumpage prices of the residual growing stock, and in the interest rate.     

Adaptive thinning strategies for mixed-species stand management with stochastic prices

This paper presents an efficient and flexible approach of determining optimal thinning strategies for mixed-species stands with stochastic timber prices. The approach aims to determine the optimal stock of each species to be maintained in the stand conditional on the observed stand state and timber prices, whereas thinning intensity is given by the difference between the existing and the optimal stocks. For demonstration purpose, the approach is applied to determine the optimal thinning strategies for an example stand of Scots pine (Pinus Sylvestris L.) and Norway spruce (Picea abies L. Karst.) in northern Sweden. The optimal stock of each species is formulated as a parametric function of stand age and stumpage prices of the respective species. A reservation price function is constructed to determine the optimal time of clearcut based on the observed stand state and timber prices. The parameters of the optimal stock-level and reservation price functions are determined by maximizing the expected present value of the stand. The results indicate that using the optimal stock-level function approach can significantly improve the thinning decisions for mixed species stand with stochastic timber prices.     

The effects of rising food prices on poverty in Mexico

We evaluate the impact of the rise in food prices during 2006–2008 on the poverty and extreme poverty rates in Mexico. We concentrate on the poor's consumption of staple foods, and analyze the change in their consumption brought about by changed prices. We also allow households receiving income from the farming and livestock sector to benefit from increases in prices of food products. We find a modest increase in poverty using 2006–2007 prices; however, there is a daunting effect on the poor once the 2008 prices are taken into account. After considering the positive effects of public policies announced in 2008, such as reduced taxes and tariffs on food products and greater subsidies to the extremely poor, the poverty rate measured through consumption increases from 25% to 33.5%, and the extreme poverty rate from 10.58% to 15.95%, given the increase in food prices. Further analysis using the theory of optimal taxes suggests policies oriented towards relieving the food price pressure on the Mexican poor should aim at lowering the prices of eggs, vegetable oil, milk, and chicken.     

Price discovery in a private cash forward market for lumber

Cash forward contracting is a common, and often preferred, means of managing commodity price risk in many industries. Despite this, little is known about the performance of cash forward markets, in particular the role they play in price discovery. The US lumber market provides a unique case for examining this issue. The Bloch Lumber Company maintains an active cash forward market for many lumber products, and publishes benchmark forward prices on their website and disseminates these prices to data vendors. Focusing on 2×4 random lengths lumber and 7/16 oriented strand board, this research examines the lead–lag relationships between the 3-month forward prices published by Bloch Lumber, representative spot prices, and lumber futures prices at the Chicago Mercantile Exchange. Results suggest that at least for 2×4 random lengths lumber, the forward prices published by Block Lumber lead both the spot price and futures price, suggesting that this private cash forward market provides some level of price discovery in the lumber markets.     

林权流转价格及其影响因素的实证研究——基于浙江省342个样本的分析

利用2007~2012年浙江省342宗林权流转数据,运用全对数线性回归模型研究木材市场价格、林分质量等关键因素对林权流转价格的影响。结果表明:木材市场价格、单位面积蓄积量和流转面积是影响流转价格的关键因素,而区域虚拟变量、便利程度虚拟变量及其交叉虚拟变量也对林权流转价格产生了不同程度的显著影响;流转期限对流转价格的影响不显著,林地价值在林权流转中没有得到体现。因此,建议确保经营主体的林权并加强森林抚育林区道路建设与改善的政策扶持。     

Structural Breaks and the Relationship between Barley and Wheat Futures Prices on the London International Financial Futures Exchange

Co-movement between futures prices can arise when commodities are substitutes. Counterintuitively, Dawson and White fail to find a significant long-run link between feed barley and wheat prices on the London International Financial Futures Exchange. This relationship is re-examined using  Johansen, Mosconi, and Nielsen's co-integration procedure that permits structural breaks. Results show evidence of co-integration and hence price discovery. There is a significant break in October 2000 following Common Agricultural Policy intervention price reductions, the barley–wheat futures market is perfectly integrated, and the barley price Granger-causes the wheat price. Modeling structural breaks in price relationships appears important.     

Price shock transmission: evidence from the wheat‐bread market value chain in Ethiopia

This study assesses the degree of vertical price transmission along the wheat‐bread value chain in Ethiopia. This is pursued by applying a vector error correction model and an impulse response analysis using monthly price data for the period 2000–2015. Our analysis considers transmission of price shocks across different market levels, including from the international and domestic wheat grain markets at the upstream to the domestic wheat bread market at the downstream of the value chain. The empirical findings indicate that significant cointegration exists across prices of the different market stages. There is a transmission from international prices to domestic prices at downstream markets, in particular to flour and bread prices. Prices at upstream markets are largely influenced by the domestic wholesale market. In general, the speed of adjustment is quite slow with a half‐life of about one year for restoring the equilibrium price relationship. As price margins between the different market stages in the value chain have substantially decreased in the last 15 years, higher transmission, and thus exposure to international market shocks, can be expected in the future. The results also show that causal relationships exist between prices at different market stages—with the wholesale market identified as the key market level where prices and price expectations are formed.     

Pseudo panel data estimation technique and rational addiction model: an analysis of cigarette,alcohol and coffee demands

We use a pseudo‐panel data approach to analyze the relationship between the consumptions of cigarettes, alcohol, and coffee in a rational addiction framework. We find that while cigarette and coffee demands fit well with the rational addiction model, alcohol demand conforms to a model with inventory effects. The results suggest that alcohol consumption increases the marginal utility derived from consumption of cigarettes. Increasing alcohol prices would decrease not only the consumption of alcohol, but also the consumption of cigarettes. On the other hand, increasing cigarette prices do not have the same effect on consumption of alcohol. The cross‐price elasticity of coffee with respect to cigarette price is positive and significant which suggests that coffee substitutes for cigarettes when cigarette prices increase. The cross‐price elasticity of alcohol with respect to coffee price is found to be negative and significant. On the other hand, Morishima elasticities of substitution indicate that cigarette, alcohol and coffee substitute each other along the indifference curve when relative prices change.     

生猪价格的省域空间溢出效应及其动态关联分析——基于空间面板模型和DY分解

目的 分析生猪价格的省际空间溢出效应,并通过各省域间价格联动效应探究我国生猪价格体系的传导机制,对治理我国生猪产业区域不均衡发展问题具有重要意义。方法 文章建立空间杜宾模型探索生猪价格的空间传导特性,引入溢出效应分解分析替代品价格、成本要素对省域生猪价格的冲击效应,并运用广义预测误差分解测定省际生猪价格关联水平及方向。结果 （1）我国生猪价格波动具有显著空间相关性和异质性,其空间集聚特征随时间推移愈发显著,产业布局呈现“高—高南部簇拥,低—低东向西扩”的空间演变特征。（2）省内替代品价格、成本要素对生猪价格波动的影响显著但作用力度有限,省际溢出效应是生猪价格发生空间传导的主导因素。（3）鸡肉价格与省内、省外的生猪价格存在密切正向关联;牛肉价格波动推动本省生猪价格同步波动;豆粕价格波动对本省或邻省生猪价格均起到正向推动作用;玉米价格变化引起本省或邻省生猪价格的负向变化。（4）辽宁、河北、吉林、河南等省的正向净关联度较大,属于波动“主导者”或“发动者”;上海、广西、重庆等省市的负净关联度较大,隶属价格波动的“接收者”;江苏、湖南、福建等省市的关联度和全国平均关联度持平,在价格波动传导体系中属于波动“中介者”。结论 有关部门应针对不同省域在生猪价格传导体系中所发挥职能的不同,分级管控生猪价格,同时促进地方畜牧业经济发展,不断优化我国生猪养殖产业区域布局。     

Synergies between Farming and Rural Tourism: Evidence from Flanders

Support for rural development and agri-environment measures is often defended on the basis of the contribution of farming to the attractiveness of rural areas and the growing rural tourism sector. Farmers may benefit from the presence of tourism by offering accommodation or selling farm products to tourists. We analyse rural tourism data for Flanders to determine whether agricultural amenities contribute to the price rural tourists are willing to pay for lodging at a farm. We find that farming practices do indeed influence the attractiveness of an area for tourism and have an impact on the prices that can be charged for accommodation. Amenities from agriculture such as permanent grassland have a positive influence on rental prices. However, the presence of intensive agricultural and livestock farming and associated polluting activities decrease the attractiveness of rural regions for tourism. Farm tourism is found to make an important contribution to the farm income and economy of a rural region. Farm tourism constituted more than 30 per cent of the farm income of certain farms. Overall, our findings support the idea of major synergies between farming and rural tourism. Strengthening this relationship may therefore be a good strategy for countryside management and rural development.     

Logs or permits? Forestry land use decisions in an emissions trading scheme

Negative carbon emissions options are required to meet long-term climate goals in many countries. One way to incentivise these options is by paying farmers for carbon sequestered by forests through an emissions trading scheme (ETS). New Zealand has a comprehensive ETS, which includes incentives for farmers to plant permanent exotic forests. This research uses an economy-wide model, a forestry model and land use change functions to measure the expected proportion of farmers with trees at harvesting age that will change land use from production to permanent forests in New Zealand from 2014 to 2050. We also estimate the impacts on carbon sequestration, the carbon price, gross emissions, GDP and welfare. When there is forestry land use change, the results indicate that the responsiveness of land owners to the carbon price has a measured impact on carbon sequestration. For example, under the fastest land use change scenario, carbon sequestration reaches 29.93 Mt CO₂e by 2050 compared to 23.41 Mt CO₂e in the no land use change scenario (a 28% increase). Even under the slowest land use change scenario, carbon sequestration is 25.89 Mt CO₂e by 2050 (an 11% increase compared with no land use change). This is because, if foresters decide not to switch to permanent forests in 1 year, carbon prices and ultimately incentives to convert to permanent forests will be higher in future years.     

Short-Run Supply Responses in the U.S. Beef-Cattle Industry

This article investigates the response of beef-cattle producers to changes in the price of cattle. Previous research has suggested that there may be a negative short-run supply response to a permanent increase in the price of cattle. We build a dynamic, rational expectations model that separates the markets for fed and unfed beef. This separation generates predictions that the supply response is generally positive, even for permanent shocks in the short run, and nests the negative supply response as a special case for appropriately restricted demand shocks.     

目标价格对新疆地方棉区棉花规模的调控效应研究

[目的]2014年起国家在新疆实施棉花目标价格试点工作,标志着新疆棉花价格正式由政府指导价时代进入市场主导时代。目标价格改革试点是完善农产品价格形成机制的一个重要举措,属于国家调控政策范畴,研究国家棉花目标价格政策对新疆棉区棉花种植规模的调控效应,对促进新疆棉花产业发展、保障国家棉花安全具有重要的意义。[方法]该研究选用新疆棉花种植面积和价格的多年时序数据,采用格兰杰因果关系检验模型和棉花价格敏感度系数,从定性与定量分析新疆棉花价格与种植规模之间关系入手,深入探讨目标价格对全疆棉区整体及各个地州棉花种植规模的调控效应。[结果]棉花价格对棉花种植规模具有滞后性影响,且对不同区域棉花种植规模的影响存在显著差异;适度的目标价格水平在一定程度上实现了调减新疆棉花种植规模、促进棉花生产向优势产区集聚、优化棉花类型结构的目标。基于此,提出新疆棉花生产发展的政策建议。[结论]目标价格政策对新疆地方棉区棉花规模调控效应显著。     

地价与房价的因果关系——全国和城市层面的计量研究

研究目的:系统地探讨地价与房价的因果关系。研究方法:计量经济学方法和比较法。研究结果:从全国层面而言,作为房价与地价一般性代表的房屋销售价格指数和土地交易价格指数之间互为长期和短期Granger因,但房价的变动对地价变动的影响力更大些。而对23个大中城市的计量研究表明,各城市地价与房价的关系不是唯一而确定的,房价的增长更多地受自身因素而不是地价的影响。研究结论:地价与房价的关系是复杂且因地而异的,以一个案例的分析结果来断定两者的关系是有失偏颇的。     

Forest proximity and residential land values

This study estimates a hedonic price equation for residential lands in some mountain counties of Colorado. Results suggest that per-acre price of land in a town is positively influenced by the town's proximity to ski resort and is negatively influenced by its proximity to forest. However, there is a positive fixed effect of having a protected forest such as a national park or wildlife refuge nearby, and the negative effect of proximity of forest is much lower with protected forests. Results suggest that increasingly bigger parcels of land command progressively lower per-acre prices.     

The Effect of Wal-Mart Supercenters on Grocery Prices in New England

The competitive price effect of Wal-Mart Supercenters on national brand and private label grocery prices in New England is examined. We use primary price data collected on several identical products from six Supercenters in Massachusetts, Connecticut, and Rhode Island and from conventional supermarkets. Taking into account demographics, store characteristics, and market conditions, we show that Wal-Mart decreases prices by 6 to 7% for national brand goods and by 3 to 8% for private label goods. Price decreases are most significant in the dry grocery and dairy departments. Moreover, Wal-Mart sets grocery prices significantly lower than its competitors.