An Ordered Tobit Model of Market Participation: Evidence from Kenya and Ethiopia

Do rural households in developing countries make market participation and volume decisions simultaneously or sequentially? This article develops a two-stage econometric method to test between these two competing hypotheses regarding household-level marketing behavior. The first stage models the household's choice of whether to be a net buyer, autarkic, or a net seller in the market. The second stage models the quantity bought (sold) for net buyers (sellers) based on observable household characteristics. Using household data from Kenyan and Ethiopian livestock markets, we find evidence in favor of sequential decision making, the welfare implications of which we discuss.     

Spatial Market Integration in the Presence of Threshold Effects

A large body of research has evaluated price linkages in spatially separate markets. Much recent research has applied models appropriate for nonstationary data. Such analyses have been criticized for their ignorance of transactions costs, which may inhibit price adjustments and thus affect tests of integration. This analysis utilizes threshold autoregression and cointegration models to account for a neutral band representing transactions costs. We evaluate daily price linkages among four corn and four soybean markets in North Carolina. Nonlinear impulse response functions are used to investigate dynamic patterns of adjustments to shocks. Our results confirm the presence of thresholds and indicate strong support for market integration, though adjustments following shocks may take many days to be complete. In every case, the threshold models suggest much faster adjustments in response to deviations from equilibrium than is the case when threshold behavior is ignored.     

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.     

Ride the trend: Is there spread momentum profit in the US commodity markets?

Some previous researchers have argued that trading strategies based on calendar spread time series momentum (STSM) can deliver significant returns (Szymanowska et al. 2014; Boons and Prado 2019), which, if true, is at odds with the efficient market hypothesis. These arguments however, do not exclude the unrealisable futures contract roll yield and are also affected by other empirical and statistical issues that may lead to misleading results. With more than 30 years of data, we investigate STSM in 22 US commodity futures markets. First, we assess whether past spread returns can predict future returns, a necessary condition for the existence of momentum. We find predictability to be very weak after correcting for the issues affecting prior research. Second, we implement STSM-based investment strategies. We compare STSM profits for individual markets and portfolios to profits generated by a simple long-only benchmark strategy that does not require any predictability. STSM does not generate returns statistically different from the benchmark trading strategy, with both strategies generating very low or negative returns. For the momentum to outperform the benchmark strategy, predictability should be three times larger than observed from real data, but would entail substantial downside risk. In sum, the empirical evidence indicates that returns from STSM-type strategies are illusive for the commodities and period studied. Our results strongly suggest that inclusion of unrealisable roll yield generates the illusion of profitable STSM trading strategies in previous research.     

对探矿权市场建设若干问题的思考

文章结合当前我国探矿权市场发育拓展、建设和规范化的实践 ,论述了探矿权市场建设中的市场类型、市场秩序、市场价格和市场行为等问题。指出 :1 不完全竞争市场是探矿权市场的最佳选择 ;2 尽快建立公平竞争的有序市场是探矿权市场建设的当务之急 ;3 探矿权市场流转价格应包括劳动投入等八大因素 ;4 应从守法纪和讲诚信两个方面对探矿权市场主体的行为进行规范。     

Rural Bangladeshi consumers’ (un)willingness to pay for low-milled rice: Implications for zinc biofortification

Zinc deficiency is a severe public health problem in Bangladesh. We examine the effects of nutritional information on rural consumers’ willingness-to-pay (WTP) for two ways to increase zinc intake through rice, the main staple crop–low-milling that gives rice grains a distinctive light brown color (a visible trait) and sets it apart from the culturally preferred high-milled white rice grain and biofortification of rice with increased zinc content (an invisible trait), which is also low-milled to retain maximum zinc content. Results of our economic experiments suggest that with nutritional information, consumers are willing to pay a premium of 4.6% for zinc biofortified rice compared to non-biofortified rice, when milled at the same level. However, results confirm the strong preference for high-milled rice by Bangladeshi consumers who discounted low-milled rice by 8%–10% even after receiving information on the nutritional benefits of biofortified or low-milled rice. We find that consumers’ WTP for the two high-zinc-low-milled rice types (biofortified and non-biofortified) is positively correlated with being a female, more educated, belonging to households engaged in non-farm activities and with children under 5 years of age. Results point to the importance of nutritional awareness campaigns for increasing zinc biofortified and low-milled rice consumption and guiding the targeting strategy for such campaigns. Given the consumer preference for high-milled rice, this study also points to the need for exploring the rice fortification strategy to address the challenge of malnutrition.     

Wholesale Market Feasibility Analysis for New Crop Development

Growers in developed as well as developing countries are seeking new or alternative crops to support rural employment, generate export earnings, and decrease crop surpluses in major crops. A key component of new crop development strategies is wholesale marketing feasibility. This article presents a model of how to analyze the feasibility of providing marketing services for new crops. The example used is a fresh-market, potato packing facility in Union County, New Mexico. The approach used in this study is applicable to growers in developing countries seeking to enter new or alternative crop markets.     

Estimating Policy Effects on Spatial Market Eff iciency: An Extension to the Parity Bounds Model

The standard parity bounds model (PBM) is extended to allow for dynamic shifts in regime probabilities in response to changes in marketing policy. The approach allows estimation of the length of the adjustment period and a statistical test for no policy effects. The extended PBM is applied to maize and wheat markets in Ethiopia. Evidence of a dynamic adjustment path is found and grain marketing reforms are found to have improved spatial efficiency in a few markets, worsened it in a few others, but generally to have had little effect on the spatial efficiency of Ethiopian grain markets.     

Modeling Farm Households' Price Responses in the Presence of Transaction Costs and Heterogeneity in Labor Markets

We develop a farm household model to analyze price responses of farm households. This model incorporates various types of transaction costs as well as labor heterogeneity. Nonproportional variable transaction costs or labor heterogeneity imply that production and consumption decisions become nonseparable, even when the household buys or sells labor. An empirical model is estimated using data from Midwest Poland. The results show that nonproportional variable transaction costs and labor heterogeneity significantly influence household behavior. Not all price elasticities, however, change significantly if these are neglected.     

森林资源产权交易市场建设的实践与探索——以南方林业产权交易所为例

介绍南方林业产权交易所基本情况。对森林资源产权交易的运行模式进行分析,得出目前存在自身定位不清,功能发挥有限、个体林农参与度不高等问题,并提出相应建议,以期为完善森林资源产权市场建设,进一步推进森林资源产权制度改革提供参考。     

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。