Inter‐ and intra‐seasonal crop acreage response to international food prices and implications of volatility

Understanding how producers make decisions to allot acreage among crops and how decisions about land use are affected by changes in prices and their volatility is fundamental for predicting the supply of staple crops and, hence, assessing the global food supply situation. This study makes estimations of monthly (i.e., seasonal) versus annual global acreage response models for the world's principal staple food crops: wheat, corn, soybeans, and rice. Primary emphasis is given to the magnitude and speed of the allocation process. Estimation of intra‐annual acreage elasticity is crucial for expected food supply and for input demand, especially in the light of the recent short‐term volatility in food prices. The econometric results indicate that global crop acreage responds to crop prices and price risks, input costs as well as a time trend. Depending on respective crop, short‐run elasticities are about 0.05 to 0.40; price volatility tends to reduce acreage for some of the crops; comparison of the annual and the monthly acreage response elasticities suggests that acreage adjusts seasonally around the globe to new information and expectations. Given the seasonality of agriculture, time is of an essence for acreage response. The analysis indicates that acreage allocation is more sensitive to prices in the northern hemisphere spring than in winter and the response varies across months.     

Maize acreage response under differential prices in the Republic of Benin,West Africa

Price response of maize acreage in Benin was estimated with a particular emphasis on whether the prices were producer prices in rural markets or retail prices in urban markets. A second difference between prices was examined through a price adjustment model which takes into account the distortions caused by local units on maize price when one is concerned with the pricing system in the private marketing network relating rural and urban areas. Urban market price specification appeared to be the most relevant statistically in explaining acreage decisions in Mono province. Price elasticity of acreage was 0.445 in this area while its value, around 0.10, was not significant for Benin as a whole. The use of adjusted urban prices enabled an increase of 5.6% of the elasticity in Mono province. The urban vs. rural difference was apparent, but the coefficients of the price variable were not significant in equations with rural prices. The latter were not as reliable as those of the urban market of Dantokpa (in Cotonou city) collected by the Institute of Statistics (INSAE) and the GTZ project.     

An Empirical Analysis of Acreage Effects of Participation in the Federal Crop Insurance Program

The extent to which crop insurance programs have resulted in additional land being brought into production has been a topic of considerable debate. We consider multiequation structural models of acreage response, insurance participation, CRP enrollment, and input usage. Our analysis focuses on corn and soybean production in the Corn Belt and wheat and barley production in the Upper Great Plains. Our results confirm that increased participation in insurance programs provokes statistically significant acreage responses in some cases, though the response is very modest in every case. In the most extreme cases, 30% decreases in premiums as a result of increased subsidies provoke acreage increases ranging from 0.2% to 1.1%. A number of policy simulations involving increases in premium subsidies are considered.     

Acreage response in Pakistan: a co-integration approach

This paper seeks to quantify the acreage responses of wheat, cotton, sugarcane and rice in Pakistan using co‐integration techniques and impulse response analysis. Results indicate that acreages of wheat and basmati rice do not respond significantly to shocks in own‐price while cotton, sugarcane and high yielding variety (HYV) rice do, and that long‐run equilibrium is re‐established after about 4 years. Irrigated area is an important determinant of acreage.     

Black Sea and World Wheat Market Price Integration Analysis

In 2008–10, Russia and Ukraine together exported an average of 29 million tons of wheat per year, and have become important players in the international wheat market. This research summarizes the short‐ and long‐run wheat price dynamics between Ukraine and Russia, and other major wheat exporters—the United States, European Union (EU), and Canada—from 2004 to 2010. Tests of market price co‐integration (Johansen maximum likelihood test and residual‐based tests) as well as threshold error correction techniques were performed for this purpose. The results suggest that Russian wheat prices were co‐integrated with EU and U.S. wheat prices but not with Canadian wheat prices. Ukrainian wheat prices were found to be co‐integrated with French wheat prices only. The estimated long‐run wheat price transmission elasticities were estimated to be equal to 1.04 between Russian and French (a representative country of the EU) wheat prices, 1.16 between Russian and U.S. wheat prices, and 1.05 between Ukrainian and French wheat prices. We also found the short‐term relationships between the co‐integrated series to be statistically significant. Price adjustments in all co‐integrated prices were found to be symmetric.     

The Impact of Biofuel Policies on Crop Acreages in Germany and France

A major concern about biofuels is that increasing biofuel feedstock demand reduces availability of crops for food and feed leading to higher food prices. This paper investigates relations between biofuel policies and prices of rapeseed, the major feedstock used for biodiesel production in Europe, and the impact of rapeseed prices on crop acreages in Germany and France. Biodiesel is an important biofuel in Europe, and Germany and France are the largest biodiesel producers in Europe. First, the various biofuel policies in Germany and France are discussed, followed by an analysis of their effects on rapeseed prices. Although theory indicates that such effects exist, we could not find empirical evidence for them. Second, using regional land use panel data from Germany and France we investigate empirically whether crop shares have been affected by rapeseed prices in the period 2000–2015 and whether these price effects changed because of biofuel policy changes. Results show that wheat shares in Germany and France did respond to rapeseed prices, but barley shares did not. Moreover, mandatory blending introduced in Germany in 2007 and production quotas introduced in France in 2005 led to a stronger effect of rapeseed prices on wheat shares, but again did not affect barley shares.     

SUPPLY RESPONSES IN THE SOUTH AUSTRALIAN POTATO INDUSTRY

The potato industry in South Australia is characterised by very unstable prices. One hypothesis for this instability is that potato growers' acreage responses follow a cobweb pattern, that is, a one year lag of acreage to price. This hypothesis is tested, together with a two year lag and a distributed lag. The distributed lag model seems the most satisfactory and gives a short-run elasticity of acreage to price of 0.36 and a long-run elasticity of 1.09. An alternative to the lagged price hypothesis is the "constant cash return" hypothesis which postulates that potatoes are grown to provide a certain cash income to permit farm development. This explanation of acreage response only seems relevant in the dairying and fat lamb areas of the State.     

Changes in Implicit Prices of Prairie Pothole Habitat

I estimate changes in agricultural land value discounts due to prairie pothole habitat. The implicit prices of pothole habitat acreage are estimated from a series of hedonic models using Manitoba agricultural land transaction data from 1990 to 2009. I find that the discount on wetland acreage increased by at least 40%, suggesting that significant unanticipated increases in the benefits of converting wetlands emerged over the course of the study period. I also estimate a series of quantile regression hedonic models. The quantile regression models indicate that the land value discounts on prairie pothole acreage as a percent of per acre sales prices are constant across the land value distribution. These results have implications for the design of habitat conservation programs, particularly those involving long‐term agreements between landowners and conservation agencies.     

SUPPLY RESPONSE OF AUSTRALIAN WHEAT GROWERS

Alternative specifications of models of the supply response of Australian wheat growers and their economic implications are considered in terms of the existence and nature of production lags, and the choice between expected prices and expected gross returns as the preferred explanator of producers' response to changing economic conditions. The analysis indicates that there are lags which are due primarily to the difficulties and costs of rapid adjustment rather than to the time required to revise expectations. The statistical results were similar for the alternative specifications of gross margins and prices as the economic decision variables. However, the price elasticities derived using the gross margins specification were about a third of those using the prices specification. The gross margins specification yielded additional information in the form of yield and input cost elasticities.     

Wheat stocks and the cointegration of wheat prices

We examine the effect of wheat stocks on the relationship between port and inland wheat prices in western Canada after the dissolution of the Canadian Wheat Board in 2012. Standard statistical tests find no evidence that the port price is cointegrated with inland prices. We argue that large harvests in 2013–2014 and 2014–2015 are responsible for this lack of cointegration. A simple theoretical model demonstrates how wheat stocks drive a wedge between inland and port prices. After including wheat stocks in the cointegrating vector, we find the expected cointegrating relationships between the port and inland prices. Using an error correction model, we show that a 10% increase in the wheat stocks reduces producer prices in Alberta and Manitoba by 6% and 4%, respectively. We conclude by discussing policy options for reducing the size of wheat stocks on the prairies.     

Government Interventions and the Production of Wheat in Saskatchewan and North Dakota: An Empirical Analysis

This paper measures the impact of different government programs relating to wheat production in Canada and the United States. Acreage and yield equations were estimated, which specifically incorporated government policy variables, using time-series data from 1960 to 1984, for wheat production in Saskatchewan and North Dakota, the two major producing regions for spring wheat in the two countries. It was found that the Canadian system of delivery quotas, while not, initially introduced as a production control program, is theoretically and empirically a more effective form of production control than the American system of acreage diversion/set-asides. A 10 percent reduction in delivery quotas reduces wheat production in Saskatchewan by an estimated 4.87 percent in the long run; farmers reduce both acreage and yield per acre in response to more restrictive delivery quotas. On the other hand, a 10 percent increase in acreage diversion/set-aside reduces wheat production in North Dakota only by an estimated 0.59 percent: farmers offset their reduction in acreage by increasing their yield per acre. Estimates of the acreage response to wheat prices in Saskatchewan are much lower than previous estimates reported in the literature. Cette communication mesure l' effet des programmes gouvernmentaux différents se rapportant à la production de blé au Canada et aux Etats-Unis. Let équations quant à la surface et le rendement sont estimées, incorporant spécifiquement des variables pour les politiques gouvernementales, utilisant les informations pour les séries-temporelles depuis 1960 à 1984, pour la production de blé en Saskatchewan et au Dakota-Nord, les deux principales régions productrices de blé au printemps des deux pays. Le système canadien des contrats de livraison, bien que ce système n' ait pas été conçu comme programme de contrôle de la production, est théoriquement et empiriquement un moyen plus efficace de contrôle de la production que le systeme américain de diversion/mise de côté des surfaces. Une diminution de 10 pourcent dans les contrats de livraison résulte en une diminution estimées à 4.87 pourcent au long terme de la production de blé en Saskatchewan; les fermiers réduisent à la fois la surface et la productivité à l' acre en réponse à des quotas de livraison plus restrictifs. D' autre part, une augmentation de 10 pourcent des surfaces en diversion/mise de côté résulte en une réduction de la production de blé au Dakota-Nord estimée a 0.59 pourcent; les fermiers contournent les réductions en surfaces par un augmentation de productivité à l' acre. Les estimés pour la Saskatchewan quand à l' ajustement en surfaces en reponsé au prix du blé sont beaucoup inférieurs aux estimés antérieurement rapportés dans la littérature sur le sujet.     

Evidence of climate change impacts on crop comparative advantage and land use

Relative agricultural productivity shocks emerging from climate change will alter regional cropland use. Land allocations are sensitive to crop profits that in turn depend on yield effects induced by changes in climate and technology. We develop and apply an integrated framework to assess the impact of climate change on agricultural productivity and land use for the U.S. Northern Great Plains. Crop-specific yield–weather models reveal crop comparative advantage due to differential yield impacts of weather across the region's major crops, that is, alfalfa, wheat, soybeans, and maize. We define crop profits as a function of the weather-driven yields, which are then used to model land use allocation decisions. This ultimately allows us to simulate the impact of climate change under the RCP4.5 emissions scenario on land allocated to the region's major crops as well as to grass/pasture. Upon removing the trends effects in yields, climate change is projected to lower yields by 33–64% over 2031–2055 relative to 1981–2005, with soybean being the least and alfalfa the most affected crops. Yield projections applied to the land use model at present-day input costs and output prices reveals that Dakotas’ grass acreage will increase by up to 23%, displacing croplands. Wheat acreage is expected to increase by up to 54% in select southeastern counties of North Dakota and South Dakota, where maize/soy acreage had increased by up to 58% during 1995–2016.     

Extensification of agriculture and deforestation: empirical evidence from Sudan

Extensification of agriculture is one of the major factors contributing to the destruction of forests in Africa. In Sudan, such horizontal expansion comes at the expense of land devoted to trees and other vegetation, thereby inducing conditions that are inimical to sustainable agricultural production. Different factors have contributed to extensification. Although high economic returns from crop (mainly sorghum) production was an important factor encouraging extensification of rainfed mechanized farming, other factors outside agriculture have also contributed to that expansion. This paper uses data from eastern Sudan and an acreage response model, to identify the most important factors influencing acreage expansion. Different measures and forms of risk were used in the acreage response model. The paper shows how policies in the energy sector can indirectly influence acreage expansion in the agricultural sector.     

基于无人机样方事后分层的作物面积估算

无人机是开展野外调查的一种新型、有效的手段,能够及时、准确地获取地面调查样方信息,为作物面积遥感估算提供精准的样方数据。研究针对无人机抽样调查的样方特点,提出了适合于无人机样方的多层次事后分层指标(多层次-异质性指标、多层次-面积规模指标)。将这些指标分别用于事后分层抽样,估算冬小麦面积。并根据变异系数(coefficient of variance,CV)对其抽样效率进行评价。多层次指标是将多种分层指标分层结果叠加形成的,能够充分反映作物种植空间分布特征、空间异质性及种植规模,可以保证作物种植面积遥感估算的精度。以河南省冬小麦面积估算为例,在冬小麦空间分布空间范围,建立300m×300m抽样框格网,作为抽样基本单元。分别利用实验设计的多层次-面积规模指标、多层次-异质性指标、面积规模指标、异质性指标计算各抽样基本单元的对应指标值。按照累计平方根法计算不同分层指标下的分层界限值。最后进行事后分层估计,计算分层效率,对分层结果与分层效率进行对比分析。计算得到以上4种分层方法的变异系数分别为1.85%、1.41%、2.16%、1.55%。结果表明,结合无人机抽样调查,利用多层次指标法进行分层,各层内作物均质性较好,能够提高农作物面积估算的精度;此外,异质性指标较面积规模指标更能提高分层的层内作物均质性与农作物面积估算精度。     

Cropping Diversity along the U.S.–Canada Border

Cropping diversity, measured by the Gini coefficient, showed neither the United States nor Canada dominated in diversity along their northern plains border during 1975–1999. While cropping was slightly more concentrated in Canada for about two-thirds of the period, dominant concentration occasionally switched between the two countries. The relative price of canola to wheat and American wheat acreage restrictions were important factors determining diversity. In the early 1990s, American farmers lagged Canadian farmers in adopting alternative crops, possibly due to incentives to maintain wheat base acreage. The decoupling of American subsidies in 1996 had not significantly affected cropping diversification through 1999.     

DISTRIBUTED LAGS AND BARLEY ACREAGE RESPONSE ANALYSIS

The need to incorporate production response lags in agricultural supply models is established, and two such lags are considered: the familiar adaptive expectations geometric lag, and a more general polynomial lag. These distributed lag supply response models are applied to Australian barley data for the period 1946-47 to 1968-69. A number of statistical problems associated with the adaptive expectations model are discussed, and in particular it is concluded that lags both in the formation of price expectations and in acreage adjustment should be considered when using geometric lag models. While the polynomial lag model does not provide useful results in the present study, its simplicity and flexibility suggest it may be useful in other studies requiring distributed lag models. The short run and long run price elasticity of barley supply estimates are compared with Gruen et al. [14] supply elasticities for the other major rural commodities, from which it appears that barley has a higher short run elasticity but a lower long run elasticity than wheat, wool and meat.     

Acreage Response In Ontario*

Acreage response functions for Ontario shelled corn, fodder corn. oats, barley, soybeans, mixed grain and winter wheat are presented. The acreage response functions are estimated using data from 1945 to 1971. The estimated equations are used to predict acreage in 1972 and 1973. In general, the acreage response of Ontario crops tends to be very elastic with respect to lagged price and yields. Le rendement par acre en Ontario dans la culture du mais àécosser, du mats de fourrage, de I'avoine, de I'orge, du soja, du blé d'automme, et des grains mélangés est présenté. Le rendement par acre est calculé de données des années 1945 à 1971. Les calculs servent à prédire le rendement par acre pour les années 1972 et 1973. En général, le rendement par acre des récoltes Ontariennes semble étre très élastique par rapport aux rendements et des prix antérieurs.     

Price Asymmetry in the International Wheat Market

Most wheat exports are accounted for by a limited number of countries with different policy regimes and specializing, for the most part, in particular classes of wheat. Under these circumstances, there is likely to be considerable interaction among the major exporting countries in the determination of wheat prices. In this paper, price linkages between the U.S. and other exporting countries (Canada, the European Union, Argentina and Australia) in the world wheat market are investigated. After determining that the direction of causality is from U. S. prices to the prices of other exporting countries, the nature of the price linkages is studied. The results suggest that the major exporting countries respond asymmetrically to U.S. price changes. The degree of asymmetry differs from one exporting country to another, Argentina and the European Union show greater response to falling prices than to rising prices, while the opposite is true for Canada and Australia.     

SUPPLY RESPONSE IN THE WHEAT-BELT OF SOUTH-EASTERN AUSTRALIA: THE IMPACT OF DELIVERY QUOTAS ON WHEAT PLANTINGS*

Supply response equations were estimated for a number of regions in south-eastern Australia using the area sown to wheat as the response variable. These equations were used to determine the effect of delivery quotas on the area of wheat sown in those regions. Results from this study indicate that delivery quotas were only effective in reducing wheat plantings in the south-eastern Australian wheat-belt in the 1970-71 season. Plantings in other seasons in which delivery quotas were applied could be explained using variables such as wheat prices and a time trend.     

河南小麦产业链各环节成本收益研究

本文通过对河南省小麦产业链各环节的深入、细致调研,利用调研的第一手数据全面剖析了小麦生产、收购、加工、销售各环节的成本收益情况.研究发现,粮食涨价是由于成本推动的,小麦制品的价格上涨主要是农业之外的因素引起的.控制粮食价格上涨的重点不在于小麦生产、收购环节,而是要限制投入品价格的不合理上涨、降低流通环节的费用、适当压缩销售环节小麦制品过大的利润空间.最后针对调研中发现的问题提出了相应政策建议.