Modeling price transmission between farm and retail prices: a soft switches approach

Vector error correction models (VECM) are used to model price transmission when farm and retail prices are cointegrated. To allow for nonlinearity in the cointegration process, researchers may specify thresholds to break the error correction process into regimes according to whether the retail price is above, below, or close to its equilibrium value given farm prices.  However, because the coefficients in a VECM can change when there is movement from one regime to another, the model can be discontinuous.  This implies sudden, “hard” regime changes. In this study, we extend the threshold VECM to include features of smooth transition autoregression (STAR) models. Our approach allows for gradual, soft regime changes.  An empirical application to retail cheese and farm milk prices is presented.     

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.     

The Effect of the Northeast Dairy Compact on Producers and Consumers, with Implications of Compact Contagion

We model and measure the effects of the Northeast Dairy Compact on prices, quantities, and producer and consumer welfare, underscoring the distribution of these effects across regions and among producers and buyers. Using 1999 as a base year, simulations show that the Compact raised the farm price of milk in the Northeast by $0.45/cwt, lowered the farm price of milk in the rest of the country by $0.02/cwt, and transferred income from producers outside the Compact region and buyers in the Compact region to producers in the Compact region. Non-Compact producer losses exceeded Compact producer gains. Similar results are found for a scenario of Compact contagion—extension of the Compact to include additional states. In both cases, the Compact changed the distribution of the costs and benefits of price discrimination as practiced by milk marketing orders. The regional distribution of the Compact's welfare effects raises again the question of the organization and stability of the federal milk marketing order system.     

Price and quantity adjustment in a dual character market The case of the Greek poultry sector

In this paper we set up, estimate and test a short-run model for the poultry sector in Greece. The model allows for the simultaneous existence of a monopolistically competitive and a competitive segment, and determines producer and consumer prices, and the quantity consumed. We provide evidence on steady-state parameters such as demand and supply elasticities, as well as on speeds of adjustment of prices and quantities. The evidence suggests that adjustment is very rapid, although quantities appear to be adjusting more quickly than prices. The model is used to examine the dynamics of adjustment to demand and supply-side disturbances.     

Rising Food Prices and Household Welfare: Evidence from Brazil in 2008

Food price inflation in Brazil in the 12 months to June 2008 was 18%, whereas overall inflation was 7%. Using spatially disaggregated monthly data on consumer prices and two different household surveys, we estimate the welfare consequences of these food price increases, and their distribution across households. Because Brazil is a large food producer, with a predominantly wage‐earning agricultural labour force, our estimates include general equilibrium effects on market and transfer incomes, as well as the standard estimates of changes in consumer surplus. Although the expenditure (or consumer surplus) effects were large, negative and markedly regressive everywhere, estimates of the market‐income effect were positive and progressive, particularly in rural areas. Because of this effect on the rural poor, and of the partial protection afforded by increases in two large social assistance benefits, the overall impact of higher food prices in Brazil was U‐shaped, with middle‐income groups suffering larger proportional losses than the very poor. Nevertheless, as Brazil is 80% urban, higher food prices still led to a greater incidence and depth of poverty at the national level.     

STATISTICAL ANALYSIS OF PRICE TRANSMISSION IN THE EUROPEAN UNION

The three-step estimator of the co-integrated system approach is used to examine the dynamic transmission of agricultural producer prices through the food marketing system in seven countries of the EU. The results suggest that even if producer and consumer prices drift apart in the short-run, for example when producer price policy changes, market forces return them to their long-run equilibrium. Tests do not reject the hypothesis of long-run ‘perfect’ price transmission for two, pigmeat-pigs and butter-milk, out of five pairs of prices, in six of the seven member countries of the EU considered here, the UK being the exception. The tests do, however, reject the hypothesis of short-run ‘perfect’ price transmission, even in its less restrictive form, across all pairs of prices in all countries.     

Spatial integration between Finnish and Dutch potato markets

This study estimated a conditional mean model for producer prices of fresh potatoes in Finland and for wholesale selling prices of fresh potatoes in the Netherlands. Unit roots were tested in the Finnish and Dutch price series. Then, an asymmetric error correction model with thresholds was estimated for potato prices between Finland and the Netherlands. Asymmetry was allowed both in short and long-run price transmission. The results suggest that the prices are cointegrated and the arbitrage system is functioning, but with a significant time lag between the Finnish and Dutch potato markets. The price response is also asymmetric in that the Finnish price moves towards a steady state equilibrium faster from above than from below the equilibrium.     

Least-cost cheap-food policies: some implications of international food aid

Many low-income countries pursue cheap-food policies in which consumers pay subsidized prices for bread, rice and other staples. This paper addresses the issue of why different governments select different food subsidy policies, using multiple instruments rather than a simple across-the-board subsidy to provide consumers with access to cheap food. It examines the optimal structure of cheap-food policies in the context of a partial equilibrium model in which the country may he large in trade, and is able to combine import subsidies or tariffs, and output taxes or subsidies, to transfer income to consumers through the market. The model allows for a marginal opportunity cost of government revenues greater than one dollar. In addition, in the model, food aid from overseas may be either given away to the consumer, or given to the government for subsequent sale in the domestic market. The results indicate that only by happenstance will a country choose to use a pure consumption subsidy or a pure import subsidy to transfer income to consumers. In addition, an increase in international food aid does not necessarily lead the government to reduce producer and consumer prices for a commodity.     

基于不同住房属性视角的土地供应规模对房价的影响

研究目的：基于住房消费品和投资品的双重属性视角分析住宅用地供应规模对房地产市场的差异化影响。研究 方法：理论分析、固定效应面板回归模型、门槛回归模型。研究结果：（1）上一年住宅用地供应面积增加 1% 可使当年 住房竣工面积显著增加 0.17%,弱于房地产投资资金对住房竣工面积所产生的 0.25% 的提升作用,该结果一定程度上 验证了住宅用地供应与住房供给之间存在生产函数渠道的影响路径;（2）基于实际房价与租金还原房价的偏离程度测 算,发现不同房地产市场投资热度下,住宅用地供应对房价影响存在双重门槛效应,门槛值分别为 2.05 和 2.92;（3）低 投资热度下,上一年住宅用地供应规模的增加可显著降低当年的房价,而高投资热度下则会起到推高房价的作用。研 究结论：住房作为消费品和投资品,存在不同的价格机制和供求规律。当住房市场以投资品属性为主导时,需求曲线 向上的刚性走势违反了一般的商品需求规律,供给曲线的右移将导致均衡价格越来越高。     

The role of retail market power and state regulations in the heterogeneity of farm‐retail price transmission of private label and branded products

Given the leading role of private label brands in the fluid milk market, it is of special interest to focus on possible differences in farm‐retail price transmission between private label and branded milk as well as the causes of heterogeneity. This article examines the heterogeneous effects of private label and branded products on price transmission in the fluid milk market using a panel threshold asymmetric error correction model. Results indicate that upward retail‐price adjustment is faster than the downward price adjustment for both private label and branded milk. The speed of adjustment of private label products is significantly faster than branded products in three different price regimes. We further investigate the reasons of heterogeneity in farm‐retail price transmission of private label milk. We find that both retailer market power and state pricing regulations contribute to the heterogeneity in asymmetric price transmission. Higher retailer market power causes retail prices of private label milk to rise faster and to fall slower. The existence of a state pricing regulation slows down the adjustment speed of retail prices of private labels back to the long‐run equilibrium, regardless of whether the retail price is low or high.     

Spatial Market Arbitrage and Threshold Cointegration

Goodwin and Piggott reported that corn and soybean prices in spatially separated markets in North Carolina exhibited threshold cointegration and that commodity prices in different markets may persistently diverge. Here, a multivariate approach is used to test for threshold cointegration and nonlinear cointegration. The results suggest that departures from the law of one price do not persist indefinitely.     

Food Aid, Food Prices, and Producer Disincentives in Ethiopia

Although the short-term aims of food aid are well conceived, strong concerns have been voiced regarding the long-term impacts of such aid on incentives for agricultural producers in recipient countries. This article examines the statistical link between food aid shipments and food prices in Ethiopia over the period 1996–2006. Monthly data from three markets and three commodities are used to estimate a system of seemingly unrelated regression models for food prices. Results indicate that previous year food aid shipments reduce prices in all producer and consumer markets. These effects, however, appear to be limited to the set of internationally traded commodities that are domestically marketed. A recursive regression procedure is used to identify the food aid threshold at which a negative aid effect emerges. Food aid shipments that constitute less than 10% of domestic production appear to be benign, but shipments above this level show signs of being disruptive to local markets. We use a simple policy simulation to argue that production-sensitive targeting, e.g., conditioning food aid on local food production, would help to circumvent disincentive effects.     

国际大米价格波动对国内大米价格的传递效应研究

［目的］国际粮食价格波动会对国内粮食价格产生影响,其影响程度和途径一直是农产品价格领域的研究热点。［方法］基于2002年1月至2017年6月的月度数据,运用Johansen协整检验和向量误差修正模型检验了国际大米价格与国内大米价格的长期均衡与短期输入关系,在考虑国内大米价格形成机制的基础上分析了国际大米价格的影响程度,并进一步检验了大米与其他粮食品种价格间的整合关系。［结果］（1）国内大米价格与国际大米价格保持长期均衡关系,短期内国内大米价格对国际大米价格波动的弹性为00226。（2）国际大米价格对国内大米价格具有显著的影响,在控制其他变量不变的前提下,国际大米价格每上涨1%,国内大米价格会上升约01%。（3）Johansen协整检验表明大米会与其他粮食品种价格保持长期整合关系,国际大米价格上涨可能会通过间接渠道传递至国内大米市场。［结论］因此不仅需要关注国际大米价格对国内大米价格的影响,还需要关注其他粮食品种对大米价格的影响。     

Structural Change and Policy Reform in the UK Dairy Sector

Estimation of a cost function for a representative sample of UK dairy producers allows future re‐structuring of the industry to be simulated using a model which incorporates producers' differential costs and milk prices. Consideration is also given to reductions in producer prices and to the introduction of an A/B quota system. The results indicate that, despite the history of quota trading in the UK, there is considerable scope for further restructuring in the industry to take advantage of differential incentives between producers. It is also projected that UK milk supply would increase if quota restrictions were removed.     

Bayesian Estimation and Selection of Nonlinear Vector Error Correction Models: The Case of the Sugar-Ethanol-Oil Nexus in Brazil

Nonlinear adjustment toward long-run price equilibrium relationships in the sugar-ethanol-oil nexus in Brazil is examined. We develop generalized bivariate error correction models that allow for cointegration between sugar, ethanol, and oil prices, where dynamic adjustments are potentially nonlinear functions of the disequilibrium errors. A range of models are estimated using Bayesian Monte Carlo Markov Chain algorithms and compared using Bayesian model selection methods. The results suggest that the long-run drivers of Brazilian sugar prices are oil prices and that there are nonlinearities in the adjustment processes of sugar and ethanol prices to oil price but linear adjustment between ethanol and sugar prices.     

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.     

Limited arbitrage in international wheat markets: threshold and smooth transition cointegration

The strength of the adjustment towards arbitrage equilibrium can be expected to be somehow proportional to the extent of market price deviations from equilibrium. In this article, threshold and smooth transition cointegration models are applied to quarterly wheat prices of three major world suppliers over the period 1973–99. Results based on arranged autoregressions of the error term of a static regression do not prove to be robust. Although non-linear models relying on a multivariate system approach yield partly contradictory results, the main evidence from the latter suggests a weakening, rather than an outright inaction, of the adjustment process in the inner regime.     

中国粮食价格波动的成因及经济效应分析

选取1978—2011年的年度数据,运用协整对中国粮价波动的成因进行实证。结果表明：粮食生产量、农业生产资料价格指数、居民消费价格指数、粮食消费量、国际粮食价格、广义货币量和粮食库存量对粮食生产价格影响显著;粮食生产量、居民消费价格指数、粮食净进口量对粮食零售价格影响显著。而粮价波动的经济效应：2种粮食价格对粮食产量的影响不同;粮价上涨农民得到的很少;不能确定物价与2种粮食价格是否有关。最后提出了相关政策建议。     

Food Price Pass‐Through and the Role of Domestic Margin Services

The recent volatility in international agricultural markets has drawn attention to the impact of rising international agricultural prices and the induced price‐insulating measures on consumer food prices. Analyses based on simulation models on this topic typically ignore the role of domestic margin services. We extend the standard Global Trade Analysis Project (GTAP) model to allow for variations in the share of domestic margin services in consumed food across countries. This approach enables us to differentiate consumer prices from producer prices. Following the extension, the results show that domestic margin services reduce the consumer food price volatility for all countries, especially in high‐income countries, where the share of domestic margin services in final food consumption is higher. The effect of price‐insulating border policies is also reduced in the extended model. We find that our extension of the GTAP model greatly improves simulations of the 2007 surge in international agricultural prices. We validate our extension of the GTAP model by showing that the econometrically estimated food price pass‐through is decreasing with income and thus, is smaller in high‐income countries.     

Farmland prices, structural breaks and panel data

Previous time series evidence has indicated that farmland pricesand cash rents are not cointegrated, a finding at odds withthe present value model of farmland prices. We argue that thisfailure to find cointegration may be due to low power of testsand to the presence of structural change representing a shiftingrisk premium on farmland investments. To accommodate this possibility,we use panel unit root and cointegration methods that are morepowerful than conventional time series methods and allow forbreaks in the cointegration relationship. Our results, basedon a large panel covering 31 US states between 1960 and 2000,suggest that the present value model of farmland prices cannotbe rejected.