Price transmission,asymmetric adjustment and threshold effects in the cotton supply chain: a case study for Vidarbha,India

This study examines price transmission asymmetries in Vidarbha's (India) cotton supply chain from 2002 to 2012. The analysis takes account of thresholds in price adjustments toward their long‐run equilibrium. The first stage considers the price dynamics between international and Indian domestic cotton prices. The second stage considers price transmission from domestic to farm gate cotton prices in Vidarbha. Results from the first stage indicate that Indian and international cotton markets are well‐integrated. In contrast, the second stage reveals significant threshold‐type nonlinearities as well as asymmetries in price transmission between domestic and farm gate prices. The short‐run dynamics suggest that the pass‐through from domestic to farm gate prices is larger when domestic prices decrease than when they increase. Moreover, back of the envelope calculations suggest that the loss in revenue for a typical farmer from a decrease in domestic price is larger than the gains from an increase in domestic price of the same magnitude. The implication is that traders benefit from price fluctuations at the expense of farmers. Evidence from fieldwork in Vidarbha suggest that asymmetries revealed in this analysis may be linked to trader's market power and inadequate market information among farmers.     

Price Transmission in Nigerian Food Security Crop Markets

This paper comprehensively examines price transmission from world, neighbour country, and internal commercial hub markets to Nigerian urban markets, as well as from urban to rural markets within the country, for seven key food security crops (maize, millet, sorghum, rice, cassava, yams and cowpeas). There are three key findings: (i) tradability matters for price transmission, but tradability varies across crops and regions. The strongest international linkages are with neighbouring countries. Rice price transmission is high across all markets, while coarse grain price correspondence is low with world prices but high with neighbour country market prices; (ii) our results imply that local conditions matter for price transmission, and are relatively more important than trade for some crops (e.g. yams, cassava) than others (e.g. imported rice, maize); (iii) larger than expected long‐run price transmission parameters in world and neighbour countries for rice and coarse grains suggest that, in these select markets, there are either large transactions costs or quality premiums that vary systematically with border prices, and/or mark‐ups captured by traders with market power.     

新一轮国际粮食价格上涨：原因及对中国市场的影响

目的 随着中国粮食进口不断增加,国内外市场联系越来越紧密。2020年下半年以来,国际市场粮食价格快速上涨,对国内粮食市场产生一定影响,分析国际市场价格上涨的原因和影响对确保国内粮食供应稳定、保障国家粮食安全具有重要意义。方法 文章分析了2019年以来小麦、大米、玉米、大豆4种粮食产品的国内外价格走势,从供需状况、贸易政策、气候变化等因素分析国际市场价格波动的原因,并探讨了国际价格对国内价格的影响。结果 当前全球主要粮食品种供应充足,库存仍处于较高水平,此轮国际粮食价格上涨主要是受到美国等发达国家宽松的货币政策以及疫情后全球消费逐步回暖的影响;但国际市场价格上涨对中国市场的影响总体有限,国内小麦、大米、玉米价格上涨的主因是国内消费回暖和生猪产能恢复带动的饲用需求快速增长,油用大豆受国际市场的影响较大。结论 为稳定国内粮食市场,避免国际市场的冲击,中国要进一步提升粮食综合生产能力,强化科技支撑,加强粮食储备管理,健全政策支持体系,并引导居民建立科学的消费观念。     

The Spatial Integration of Paddy Markets in Vietnam

This paper examines whether there is spatial integration between and within paddy markets in the north and south of Vietnam. The empirical model developed uses estimates of transfer costs to generalise Ravallion's model of spatial market integration to allow for threshold effects. A sequential testing strategy is used to test for market segmentation, the number of thresholds, long‐run integration, informational efficiency and the Law of One Price within an error‐correction framework. We find neither threshold effects nor weak evidence of paddy market integration between northern and southern Vietnam. There is, however, evidence of both threshold effects and stronger market integration within the Red and Mekong River deltas. Whenever price spreads exceed their thresholds, at least 60% of price changes are transmitted between regional markets within a month. Nonetheless, the instantaneous version of the Law of One Price only holds for a few regimes and market pairs. These results suggest that national level policies cannot be relied upon to stabilise or support paddy prices in Vietnam. Instead, policies need to be designed with the specific production, consumption and marketing characteristics of northern and southern Vietnam in mind.     

Government intervention and market integration in Indonesian rice markets

Long-run spatial price relationships in Indonesian rice markets and factors affecting the degree of market integration are evaluated using multivariate cointegration tests with weekly price data for the 1982-1993 period. The analysis includes evaluation of pre-self-sufficiency and post-self-sufficiency periods as well as Cot the entire period. The cointegration tests for entire Indonesian rice market, represented by the nine most relevant price series, indicate that relative to the pre-self-sufficiency period, the post-self-sufficiency period has a smaller degree of market integration. The change of the degree of market integration over time indicates that rationalizing of the Indonesian rice price policy beyond 1984 rice self-sufficiency has resulted in a less integrated market. This suggests that the policy shift has allowed the government to decrease its intervention without significantly decreasing market integration, indicating that the private sector is responding to price signals appropriately. It is possible that further reduction in intervention through widening the band between the floor and ceiling price could be accomplished without greatly affecting market integration. Regression results show that government intervention in terms of rice procurement significantly influenced market integration during the period of post-self-sufficiency (1985-1993) and the entire period of 1982-1993. This indicates that this aspect of government intervention has had positive influences on market integration, in contrast to distribution efforts, which were not found to be statistically significant, Procurement prices may be high, and could perhaps be lowered, reducing program costs. Regional per capita income is also found to be positively related to highei levels of market integration, suggesting that in periods of economic growth, government intervention may be decreased, thereby reducing program costs.     

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。     

Agricultural price transmission elasticity: importance of controlling for unobserved common factors

A voluminous amount of the literature estimates price transmission from world markets to domestic markets ignoring unobserved factors that commonly affect domestic markets. This article reevaluates the long‐run and short‐run transmission elasticity of world food price shocks to domestic markets using a “common factor framework” that takes unobserved common factors that are correlated with regressors into consideration. In the estimation, annual price data for rice, wheat, and maize for a panel of developed and developing countries that are observed over the period of 1960–2007 are used. The results from a common factor framework to those that do not account for common factors are then compared. Our findings suggest that ignorance of common factors is likely to result in upwardly biased elasticity estimates.     

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.     

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.     

Influence of Trade Policies on Price Integration in the World Beef Market

The article develops three hypotheses about how policy interventions in major trading nations influence price integration in the world beef market. Simple correlation coefficients, tests for significant differences between coefficients, and Granger causality tests are used to test the hypotheses. First, segmentation between prices in Foot and Mouth Disease (FMD)-free and FMD-endemic countries is found, but it is much less than previously assumed. Second, European Community policies that closed the E.C. import market have isolated prices in the E.C. from other markets. These policies also led to greater integration among prices in FMD-free and FMD-endemic market segments by forcing exporters from both segments to compete directly in new import markets. Third, the U.S.A. is found to be the price leader in world beef markets, due not only to market size, but also to U.S. policies that allow transmission of price information from the U.S. market to the world market but not vice versa.     

价格支持、政策调整及粮食市场波动

目的 为了估计价格支持政策对不同粮食品种期现货价格波动的直接影响,实证分析和比较了政策及其调整对粮食期现货价格波动实施效果的影响,为深化粮食价格形成机制改革提供一定的理论参考和实证支撑。方法 文章利用稻谷、小麦、玉米和大豆的现货与期货价格日数据,将政策以虚拟变量的形式引入GARCH模型实证分析最低收购价政策、临时收储政策及其调整对平抑粮食期现货市场波动的作用。结果 价格支持政策对粮食价格波动产生了显著影响,最低收购价政策能够明显降低稻谷和小麦现货市场的波动程度,但对期货市场波动的作用则相反;玉米和大豆临时收储政策的取消导致现货市场波动性提高,而对期货市场波动的影响存在差异。结论 价格支持政策具有降低价格波动的作用效果,政策调控效果与实施品种的国内供求及市场形势、国内外市场的联系程度密切相关,政策的完善还需关注对期货市场波动的影响。     

Testing vertical price transmission for Vietnam's Robusta coffee

Vietnam has undergone market reforms over the last three decades; and as a consequence, the coffee sector has become increasingly market‐driven. The success of the government's liberalisation policies in terms of market efficiency is investigated by examining the transmission of both positive and negative price changes for Robusta coffee between export and farmgate prices. We used a threshold vector error correction model and high‐frequency daily data. The primary result here is that of a symmetric price transmission between export and farm‐level prices. This result holds when tested with weekly price data, derived from the daily data. Farmgate prices respond faster to decreases than increases in export prices when the long‐run deviation exceeds a certain threshold. These price changes are transmitted within several days. This research also confirms the importance of transaction costs, and other price frictions mostly ignored in prior analyses for coffee.     

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。     

World market integration for export and food crops in developing countries: a case study for Mali and Nicaragua

Using a generalized error correction model, this article measures and compares market integration for export cash crops versus imported food crops for Mali and Nicaragua, and computes transmission elasticities between changes in the goods’ border and domestic prices. Both Mali and Nicaragua obtain the bulk of their export revenue from a particular agricultural commodity—cotton for Mali and coffee for Nicaragua—and both import the same key staple food of rice. To reap the economic gains from this trade specialization, the two countries’ agriculture must be well‐integrated into world markets. The two countries present an important policy contrast that affects their degree of world market integration and price transmission. In Mali, a parastatal enterprise controls its cotton industry, while Nicaragua has less state direction over agriculture. Reflecting this difference, the results show that for both its main export and import commodity, Nicaragua is more integrated into world markets and has higher price transmission than Mali. The results for Nicaragua also show much higher integration and price transmission for its main agricultural export (coffee) than its major import (rice).     

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.     

Liberalization of agricultural input markets in Bangladesh: process,impact, and lessons

The study takes a historical perspective to trace the path of evolutionary reforms in agricultural input markets of Bangladesh. It estimates the magnitude of the impact of these reforms on rice production, the most important crop in Bangladesh agriculture. It is estimated that the production of rice could have been 20-32% lower than the level of 1992/1993, depending on the rice price that would have prevailed under alternative scenarios. The 20% credit to market reform relates to a real rice price level 19% higher than the actual 1992/1993 prices. The 32% credit to reform relates to the actual 1992/1943 price levels. The lower contribution of reform (20%) to increased production implies a loss to consumers not accounted for in the production benefit of reform, while the higher contribution (32%) of reform entails no loss to consumers. The bottom-line conclusion is that Bangladesh, without the market reforms described in the paper, would have reverted back to the situation of regular food crisis and high rice prices, as was the case historically. The analysis of the process of reform provides interesting lessons for developing countries. A gradual process based on a well-designed sequencing of various steps of market reform, particularly in the case of fertilizer, was a crucial factor for success. Careful monitoring during the period of transition is another crucial factor that has to be institutionalized in the system. Second generation problems of market reforms, particularly the emergence of an oligopolistic market structure, are possible and warrant a cautionary watch.     

Transaction Cost Thresholds in International Rice Markets

Recent episodes of high and volatile prices for grains such as rice have raised concerns about their implications for hunger and poverty. We model price relationships between international rice prices and 221 domestic prices in 47 developing countries that import rice. We use a threshold vector error correction model that accounts for transaction costs of trade in spatial price transmission, and an improved regularised Bayesian threshold estimator for threshold models. Our results show that threshold values are higher after 2008 than before, which suggests that transaction costs in international rice trade have increased in recent years. Threshold values are highest for Latin American countries followed by African and Asian countries, and higher for retail than for wholesale prices. Since 2008, price transmission is slower in countries that responded to high and volatile prices with domestic market‐based interventions such as price controls and faster in countries that responded by lowering tariffs and by implementing production support measures.     

Spatial Integration of Wheat Markets in India: Evidence from Cointegration Tests

Using the maximum likelihood method of cointegration, this paper empirically evaluates intra-state and inter-state spatial integration of wheat markets in India. The cointegration tests provide strong evidence in favour of spatial integration of the regional wheat markets. Even though the regional markets are geographically dispersed, the prices across different market centres within and across the selected states have exhibited long-run spatial linkages, suggesting that all the exchange locations are integrated and the prices provide relevant market signals. There are several implications of these results for agricultural price policy and food market liberalization programmes.     

Testing for spatial market integration: evidence for Colombia using a pairwise approach

We examine the extent of spatial market integration in Colombia using consumer price index data for 153 consumer goods in 13 cities. An econometric analysis of the time‐series properties of all the possible city price differentials reveals that market integration tends to occur more frequently in unprocessed food products, as opposed to processed foods, other traded and nontraded products. The results also support the view that, except for nontraded products, the speed at which prices adjust to the long‐run equilibrium is slower for cities that are farther apart.     

Cross country maize market linkages in Africa: integration and price transmission across local and global markets

In order to study short‐run price shock propagation, we model twenty seven Sub‐Saharan Africa (SSA) domestic maize markets within a Global Vector Autoregression framework. The main purpose is to fully embed multilateral trade flows as a way to better structure local price transmission dynamics and interdependencies, and get a more comprehensive picture of food price shocks propagation. We found significant between‐country market contagion and prompt regional price shock propagation when trade connection exists. Yet, the integration of SSA domestic maize markets within the continent and with global markets remains generally weak. Furthermore, under regular market conditions, most local price series appear to be more responsive to regional neighbors than to global shocks.