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.     

Global market shocks and poverty in Vietnam: the case of rice

World food prices have experienced dramatic increases in recent years. These “shocks” affect food importers and exporters alike. Vietnam is a major exporter of rice, and rice is also a key item in domestic production, employment, and consumption. Accordingly, rice price shocks from the world market have general equilibrium impacts and as such, their implications for household welfare are not known ex ante. In this article, we present a framework for understanding the direct and indirect welfare effects of a global market shock of this kind. We quantify transmission of the shock from global indicator prices to domestic markets. Then we use an applied general equilibrium model to simulate the economic effects of the price changes. A recursive mapping to a nationally representative household living standards survey permits us to identify in detail the ceteris paribus effects of the shock on household incomes and welfare. In this analysis, interregional and intersectoral labor market adjustments emerge as key channels transmitting the effects of global price shocks across sectors and among households.     

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.     

Enhancing food security in South Sudan: the role of markets and regional trade

South Sudan faces serious problems of food insecurity due to low levels of domestic food production, periodic droughts, widespread poverty, and since late 2013, renewed armed conflict. This article explores market price behavior using cointegration analysis and estimates the effects of production and trade shocks through multimarket model simulations. We show that market prices in the capital city, Juba, of both maize and sorghum are cointegrated with import parity prices of these cereals sourced from Uganda, consistent with observed trade flows. Model simulations, using econometrically estimated demand parameters, suggest that private sector imports of maize and wheat would greatly mitigate the potential fall in consumption in the case of a decline in domestic cereal production. Other simulations indicate that if total imports of cereals are reduced by one‐third (still more than two times the levels of food aid in 2013) because of disruptions to private market flows, domestic prices of cereals could rise by 45% or more. The article concludes that whatever measures are taken involving national food security reserves, it is crucial that government policy serves to maintain incentives for private sector imports to avoid destabilizing market supplies, domestic prices, and ultimately, food consumption of the poor.     

Shocks to food market systems: A network approach

In order to better understand how cross-border price shocks are transmitted to domestic food markets, we augment an error correction model with a network approach and apply it to Tanzania. We show the following. First, Dar es Salaam, Tanzania's largest city and port, is not a significant influence. Second, demand shocks emanate primarily from border markets that may serve as conduits for informal trade. Third, market linkages differ considerably across seasons and commodities. Fourth, prices in areas with high production potential are especially sensitive to systemic shocks. More broadly, we show that a network approach in conjunction with time series analysis can enhance our understanding of the origins and channels through which shocks are transmitted to food markets.     

The linkage between the U.S. ethanol market and developing countries’ maize prices: a panel SVAR analysis

The major expansion of U.S. ethanol production raises concerns about the potential detrimental impacts on developing countries’ agricultural prices, farm income, and food security. To assess the sensitivity of maize prices to ethanol production, this study explores the linkage between the U.S. ethanol market and developing countries’ maize prices. The econometric approach, based on a panel structural vector autoregression model, captures market interdependencies and the likelihood that developing countries’ responses are both heterogeneous and dynamic. The results indicate that the U.S. ethanol market's impacts on maize prices in developing countries are heterogeneous and that coastal countries are more susceptible to U.S. economic shocks. The estimates also suggest that countries more dependent on food imports and/or receiving U.S. food aid are at a higher risk of being affected by such shocks. Overall, the results indicate that those countries with the greatest sensitivity and exposure to global agricultural commodity markets could benefit from domestic policies and international assistance, which reduce their exposure to impacts from the U.S. maize market.     

Spatial price efficiency in Mozambique's post-reform maize markets

Maize (Zea mays) shortages and maize price instability continue to occur in Mozambique in spite of policy reforms and great capacity for increased production in northern Mozambique. This study measured the efficiency of spatial maize price arbitrage in Mozambique's post‐reform period. Spatial price inefficiency does not seem to explain why food shortages continue to occur in Mozambique, suggesting nonprice market constraints such as poor infrastructure and poor market institutions as more likely explanations. Baulch's spatial efficiency test indicated that it is not profitable to ship maize from northern surplus maize regions to southern Mozambique. Records of interregional maize shipments show that indeed grain is not being shipped from the north to the south. Market liberalization may have improved spatial price efficiency, but high transfer costs still limit trade and potential benefits from freeing markets. Under these circumstances, food shortages and price instability are likely to continue.     

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.     

Applying cointegration and error correction to measure trade linkages: maize prices in the United States and Mexico

The impact of U.S.‐grown maize on Mexican markets is a subject of heated debate, and is complicated by limited substitution between white and yellow maize as well as regional price differences within Mexico. This article improves on previous analyses using a detailed data set of white maize prices reported weekly in 11 states across Mexico from 1998 through 2005. Using cointegration analysis and the error‐correction model, we find that prices between the United States and Mexico do not share a common long‐run relationship. Within Mexico, prices in Michoacán and Oaxaca are only weakly related with prices in neighboring states, whereas prices in Sinaloa and Jalisco exert considerable influence on prices elsewhere in Mexico. We conclude that, despite North American Free Trade Agreement (NAFTA), white maize prices in Mexico are determined by local conditions including particularly the degree of integration to other regions within Mexico.     

Fighting global food price rises in the developing world: the response of China and its effect on domestic and world markets

This article addresses how China is being affected by and is responding to the world food crisis. So far, Chinese officials have responded to higher world prices by drawing down stocks and limiting exports of major grains. These policy instruments were not available for soybeans, so domestic prices of soy and other oilseeds have risen with international prices. Using a global CGE model, we show that the initial world price rise was largely due to higher world oil prices and demand for biofuels as opposed to other factors, especially in maize and soybeans. China's response to this shock has kept domestic grain prices low relative to world grain markets and to domestic soybean prices. As grain stocks are depleted, however, demand growth will push domestic prices back into alignment. Anticipating this pressure on consumers and accelerating supply response through public investment will facilitate adjustment.     

Nontraded food commodity spatial price transmission: evidence from the Niger millet market

Using an Augmented Factor Vector Autoregressive (FAVAR) Model, this study analyzes spatial millet prices transmission in Niger. Our results did not find condition for millet markets integration existence. However, the Granger causality tests and impulse response functions from the estimated short‐term dynamic as FAVAR model revealed the existence of leading markets whose millet prices affect a maximum number of other regional millet prices, while some regions seem to be isolated from trade or information flows. Furthermore, the significance of a shock depends also on the characteristics of the region where it originates in terms of millet demand or supply, indicating that the region to target and where the price shock originated matter for the policies’ success.     

Agricultural price distortions: trends and volatility,past, and prospective

Historically, earnings from farming in many developing countries have been depressed by a pro‐urban bias in own‐country policies, as well as by governments of richer countries favoring their farmers with import barriers and subsidies. Both sets of policies reduced global economic welfare and agricultural trade, and added to global inequality and poverty. Over the past three decades, much progress has been made in reducing agricultural protection in high‐income countries and agricultural disincentives in developing countries. However, plenty of price distortions remain. As well, the propensity of governments to insulate their domestic food market from fluctuations in international prices has not waned. Such insulation contributes to the amplification of international food price fluctuations, yet it does little to advance national food security when food‐importing and food‐exporting countries equally engage in insulating behavior. Thus there is still much scope to improve global economic welfare via multilateral agreement not only to remove remaining trade distortions but also to desist from varying trade barriers when international food prices gyrate. This article summarizes indicators of trends and fluctuations in farm trade barriers before examining unilateral or multilateral trade arrangements, together with complementary domestic measures, that could lead to better global food security outcomes.     

Nonlinear adjustments in deviations from the law of one price for wholesale hog prices

This article applies the Band‐Threshold Autoregression (Band‐TAR) model to investigate whether the law of one price (LOOP) holds in Taiwanese wholesale hog markets during the period from May 1987 through December 2003. We find evidence of a nonlinear mean reversion in deviations from the LOOP for relative hog prices. Our empirical study confirms the presence of thresholds and provides strong evidence in support of the view that the regional hog markets have been tightly integrated in Taiwan and that the wholesale hog market in Taiwan is an efficient market economy. Furthermore, the estimated half‐lives from the nonlinear generalized impulse response analysis are as short as four months.     

Economic impacts of El Niño southern oscillation: evidence from the Colombian coffee market

El Niño Southern Oscillation (ENSO) is a naturally occurring phenomenon that affects weather around the world. Past ENSO episodes have had severe impacts on the economy of Colombia. We study the influence of ENSO on Colombian coffee production, exports, and price. Our structural econometric specification is consistent with an economic model of the market for Colombian coffee which, in the short run, is characterized by a downward‐sloping demand curve and by a vertical supply curve. We show that El Niño (i.e., positive shocks to ENSO) is beneficial for Colombian production and exports and decreases the real price of Colombian coffee. On the contrary, La Niña (i.e., negative shocks to ENSO) depresses Colombian coffee production and exports and increases price. However, the overall impact of ENSO shocks is small. Both in the short run and in the long run, shocks to international demand for Colombian coffee are more relevant than supply‐side shocks in Colombia in explaining the dynamics of the price of Colombian coffee. Our results suggest that a given coffee price shock can have beneficial, detrimental, or negligible effects on the Colombian economy, depending on its underlying cause. As a consequence, policy responses to coffee price shocks should be designed by looking at the causes of the shocks.     

Land use and economic effects of alternative biofuel policies in Brazil and the United States

Being the two largest ethanol producers in the world, biofuel policies in Brazil and the United States affect both their domestic markets and the global food and biofuel economy. In this article we develop a price endogenous mathematical programming model to simulate and analyze the impacts of biofuel mandates and trade distortions on land use, agricultural commodity and transportation fuel markets, and global environment. We find that an 80% increase in total biofuel production from its 103 billion liter baseline level to the mandated 183 billion liter level in 2022 can be achieved with less than 2% increase in total cropland use in both countries. In the United States, this would occur with cellulosic biofuels meeting nearly half of the biofuels consumed and produced largely on cropland pasture and corn ethanol meeting the rest of the mandate and resulting in a 2% increase in corn price. In Brazil, the expansion in sugarcane production would be achieved by reducing land under pasture and a marginal increase in intensification of livestock production. In the aggregate, biofuel policies increase economic surplus in both countries by 1% and redistribute the benefits from agricultural consumers to agricultural producers and the fuel sector. Finally, we also find that full implementation of the mandates in North America, China, and the European Union would reduce the global life‐cycle global greenhouse gas emissions by about 5%.     

Impacts in Uganda of rising global food prices: the role of diversified staples and limited price transmission

This study assesses the potential impact of rising world food prices on the welfare of Ugandan households. While Uganda experienced sharply higher food prices in 2008, as a landlocked, food‐exporting country the causes of those price changes were mainly regional and indirect rather than directly transmitted from global markets. Using trade volumes, food prices, and household survey data we describe how Uganda, unlike some other countries, is partially shielded from direct impacts of global food price movements. Although the majority of Ugandans are net food buyers, the adverse impact at household‐level of rising global prices is moderated by the relatively large quantity and range of staples consumed that come from home production. Moreover, several of these are not widely traded. Some population groups in Uganda are vulnerable to rising food prices, however, primarily those for whom maize is an important staple, including those dependent upon humanitarian relief and the urban poor. Only a relatively small group of Ugandan households will benefit directly and immediately from rising food prices—the significant net sellers of food crops constituting between 12% and 27% of the population. In this assessment we do not estimate the level and extent of wider second round effects from these higher prices.     

Market integration between surplus and deficit rice markets during global food crisis period

Applying the maximum‐likelihood method of co‐integration, this study analysed spatial market integration between an adjacent rice surplus market (India) and deficit markets (Bangladesh and Nepal). The main focus is on the government policies of these three rice‐producing countries which have been imposed to reduce domestic price volatilities in rice markets during the recent ‘global food crisis’ in 2007–2008. The co‐integration tests find that domestic rice prices of India, Bangladesh and Nepal are integrated both in short‐run and long‐run periods despite the imposition of export restriction policies by India. The reason that prices are transmitted so effectively is most likely to be the widespread informal cross‐border trade through the porous borders among India, Bangladesh and Nepal.     

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.     

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 transmission of world maize price to South African maize market: a threshold cointegration approach

This article seeks to provide an explanation for the relationship between domestic maize price in South Africa and world maize prices in order to evaluate comovement and transmission of world prices to domestic prices in sub‐Sahara African countries. This is done by comparing nested and nonnested models that capture different forms of nonlinearity in the price spread. Adopting a Bayesian approach that allows for comparison of models using Bayes factor, we found that the relationship between South African price and world price for maize indicates the presence of nonlinearity in price transmission with three regimes that is triggered by the price spread in previous period.