Are Shocks Transitory or Permanent? An Inquiry into Agricultural Commodity Prices

This paper contributes to the contentious topic of whether shocks to agricultural commodity prices are permanent or transitory. This is an important issue with regards to forecasting, economic modelling of agricultural prices and risk management. Past studies have not accounted for important characteristics of agricultural prices that matter when testing whether shocks to prices are permanent or transitory. These include the presence or absence of a deterministic trend, the possible break in the trend, non‐stationary volatility, and the problem of the initial deviation of commodity prices from their long‐run mean or trend. We conduct a comprehensive test that incorporates all these characteristics known to plague agricultural commodity prices. Though the conclusion is mixed, the balance is in favour of agricultural price shocks being permanent in nature. This result departs from the general view that in theory, agricultural prices should be stationary, suggesting that the controversy of whether shocks to agricultural prices are temporary or permanent is not yet over.     

The Variable Response of Agricultural Supply to World Price Instability in Developing Countries

This paper analyses the effect of world price instability on the agricultural supply from developing countries and determines to what extent this effect is dependent upon the macroeconomic environment. Producers from agricultural commodity‐exporting countries are particularly vulnerable to the fluctuations of world prices: they are widely exposed to price shocks and have little ability to cope with them. Nevertheless, the effectiveness of risk‐coping strategies is conditioned by the influence of macroeconomic factors (infrastructure, inflation and financial deepening). Thus country‐specific price indices are established, and the response of production indices to price instability indices is estimated by using a panel model including macroeconomic variables which interact with price instability. Such analysis is based on a sample of 25 countries between 1961 and 2002. The results highlight a significant negative effect of the world price instability on supply, and further show that high inflation, weak infrastructure and a poorly developed financial system exacerbate this effect.     

The impact of commodity price shocks among regional economies of a developing country

Volatile commodity prices have become commonplace in the world economy. Although is widely accepted that commodity‐rich countries are affected by this phenomenon, information about how commodity price shocks impacts their regional economies is scarce. This work analyses how shocks in copper prices impact the economies of the major copper‐producing regions in a developing country, such as Chile. To achieve this goal, a two‐step method is implemented. First, we estimate long‐term copper prices using the Wets and Rios approach (2015) and these estimates are then contrasted with those forecast by the Chilean public advisory committee. Second, a general equilibrium model is implemented to simulate the effects of both expansive and restrictive copper price cycles within major producing regions in Chile. Our results show that the proposed approach yields more homogeneous price projections than those made by the Chilean Government, which, in turn, are very close to variations in response to negative shocks. The price simulations confirm that price cycles affect the savings of government and business, which directly dampens regional production, mainly via investment, capital mobilisation and diversification of production. Because of this, fiscal revenues generated by copper sales act as a trade cycle term multiplier in regional economies. Overall, within copper‐producing regions, we suggest implementing long‐term policies to improve profit distribution efficiency.     

Monetary policy shocks and the dynamics of agricultural commodity prices: evidence from structural and factor‐augmented VAR analyses

Fluctuation in commodity prices is a significant and timely issue to be studied. This study is to examine the impact of monetary policy and other macroeconomic shocks on the dynamics of agricultural commodity prices. The major contributions of this study are twofold. First, unlike other studies that use indexes, this study analyzes the commodities individually, affording the inclusion of commodity‐specific fundamentals such as the level of inventory—an important determinant of commodity price—in a structural VAR framework. Second, it exploits a rich data set of agricultural commodity prices which includes commodities that are usually overlooked in the literature, and extracts a common factor using the dynamic factor model to understand the extent of comovement of the prices and to gauge the extent to which macroeconomic shocks drive the “comovement” in a factor‐augmented VAR (FAVAR) framework. The findings show that monetary policy, global economic conditions, and the U.S. dollar exchange rates play an important role in the dynamics of agricultural commodity prices.     

Modeling regime‐dependent agricultural commodity price volatilities

In stark contrast to financial markets, relatively little attention has been given to modeling agricultural commodity price volatility. In recent years, numerous methodologies with various strengths have been proposed for modeling price volatility in financial markets. We propose using a mixture of normals with unique GARCH processes in each component for modeling agricultural commodity prices. While a normal mixture model is quite flexible and allows for time varying skewness and kurtosis, its biggest strength is that each component can be viewed as a different market regime and thus estimated parameters are more readily interpreted. We apply the proposed model to ten different agricultural commodity weekly cash prices. Both in‐sample fit and out‐of‐sample forecasting tests confirm that the two‐state NM‐GARCH approach performs better than the traditional normal GARCH model. A significant and state‐dependent inverse leverage effect is detected only for pork in the regime where the price is expected to drop, indicating the volatility in this regime tends to increase more following a realized price rise than a realized price drop.     

The impacts of biofuels targets on land‐use change and food supply: A global CGE assessment

We analyze the long‐term impacts of large‐scale expansion of biofuels on land‐use change, food supply and prices, and the overall economy in various countries or regions using a multi‐country, multi‐sector global computable general equilibrium model augmented with an explicit land‐use module and detailed biofuel sectors. We find that an expansion of biofuel production to meet the existing or even higher targets in various countries would slightly reduce GDP at the global level but with mixed effects across countries or regions. Significant land re‐allocation would take place with notable decreases in forest and pasture lands in a few countries. The expansion of biofuels would cause a moderate decrease in world food supply and more significant decreases in developing countries like India and Sub‐Saharan Africa. Feedstock commodities (sugar, corn and oil seeds) would experience significant increases in their prices in 2020, but other price changes are small.     

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.     

Evaluating price transmission between global agricultural markets and consumer food price indices in the European Union

This paper uses error correction models to evaluate the extent to and speed at which world agricultural commodity price movements affect consumer food prices in the European Union member states. We consider three types of world commodity price indices, each containing different commodities and weighting criteria. Results reveal a long‐run relationship between world agricultural commodity and consumer food prices in over half of the member states. Consumer prices in different member states and categories of member states respond differently to specific world price indices, suggesting that there are disparities in the structure and the efficiency of their food markets. The eurozone founders generally have lower transmission elasticities. This should be taken into account when predicting the impacts of extreme world price volatility and consumer food price rises, prompting governments to pay attention to the most vulnerable households.     

World Commodity Prices and Domestic Retail Food Price Inflation: Some Insights from the UK

We focus on two aspects of the links between world commodity prices and retail food price inflation: first, the effects of exchange rates and other input costs, and second; the effects of the duration of shocks on world commodity markets, not just the magnitude of price spikes (the latter often commanding most attention). The UK offers a natural and rather unexplored setting for the analysis. Applying time series methods to a sample of 259 monthly observations over the 1990(9)–2012(3) period we find substantial and significant long‐term partial elasticities for domestic food price inflation with respect to world food commodity prices, the exchange rate and oil prices (the latter indirectly via a relationship with world food commodity prices). Domestic demand pressures and food chain costs are found to be less substantial and significant over our data period. Interactions between the main driving variables in the system tend to moderate rather than exacerbate these partial effects. Furthermore, the persistence of shocks to these variables markedly affects their effects on domestic food prices.     

Higher fuel and food prices: impacts and responses for Mozambique

Rising world prices for fuel and food represent a negative terms‐of‐trade shock for Mozambique. The impacts of these price rises are analyzed using various approaches. Detailed price data show that the world price increases are being transmitted to domestic prices. Short‐run net benefit ratio analysis indicates that urban households and households in the southern region are more vulnerable to food price increases. Rural households, particularly in the North and Center, often benefit from being in a net seller position. Longer‐term analysis using a computable general equilibrium (CGE) model of Mozambique indicates that the fuel price shock dominates rising food prices from both macroeconomic and poverty perspectives. Again, negative impacts are larger in urban areas. The importance of agricultural production response in general and export response in particular is highlighted. Policy analysis reveals difficult trade‐offs between short‐run mitigation and long‐run growth. Improved agricultural productivity has powerful positive impacts, but remains difficult to achieve and may not address the immediate impacts of higher prices.     

Effects of international shocks and domestic macroeconomic policies upon Brazilian agriculture

An identified vector-autoregressive model is used to analyze the transmission of external commodity shocks to the Brazilian economy. The effects of the interaction between domestic macroeconomic (monetary and exchange rate) policies and external shocks to agricultural commodity (raw material and food) prices and crude oil price upon domestic (agriculture/industry) terms of trade are estimated.     

Tracing the Effects of Agricultural Commodity Prices and Food Costs

We estimate a system of product and input-demand equations for food-processing industries to trace the links among farm commodity prices, food-processing costs, and food prices. Disembodied technical change, which likely reflects increasing consumer demand for convenience and product variety, has sharply reduced agricultural materials demand relative to most other food-processing inputs. This implies weakening impacts of farm price shocks on food prices. But improving quality and falling relative prices for agricultural inputs, in combination with increasing factor substitution, has counteracted these forces to encourage greater usage of agricultural inputs in food processing, and limit these trends.     

A simple model of endogenous agricultural commodity price fluctuations with storage

A debate has been raging for centuries regarding the effects of interannual storage on commodity prices. Most analysts consider storage to function as a price stabilizer, while others place it at the core of an explanation of intriguing features of commodity price series, such as skewed distributions. Most studies have been developed in the context of the theory of competitive storage where random shocks affect supply or demand. Recently, the endogenous chaotic behavior of markets has become another possible hypothesis regarding the origin of commodity price fluctuations. We develop a nonlinear cobweb model with intra‐ and interannual storage, risk averse agents, and adaptive expectations. Like the theory of competitive storage, this nonlinear cobweb model with storage can reproduce some of the stylized facts of agricultural commodity prices (autocorrelation of first rank, low kurtosis, and skewness). In addition, the effects of storage on price variation are mixed. In the presence of interannual storage, chaotic price series show less variation compared to a situation without interannual storage but we find that storage contributes to the endogenous volatility of prices by making chaotic dynamics more likely.     

Post–Uruguay Round price linkages between developed and developing countries: the case of rice and wheat markets

The Uruguay Round Agreement on agriculture attempted to lower distortions in global agricultural markets. However, the significant fall in commodity prices in the late 1990s may have reduced the incentives for both developed and developing countries to better integrate into world markets. This study analyzes price linkages and adjustment between developed and developing countries during the post–Uruguay Round period. Prices of two key commodities, long‐grain rice and medium‐hard wheat, are assembled for major exporters and producers. Results of multivariate cointegration analysis suggest partial market integration between developed and developing countries in the post–Uruguay Round period. Developed countries are found to be price leaders in these two markets, and in most cases, changes in their prices have relatively large impacts on those of the developing countries. Developing countries (e.g., Vietnam and Argentina) have faced considerable price adjustment due to changes in the developed countries' prices.     

Food price increases and net food importing countries: lessons from the recent past

Recent increases in food and other commodity prices have highlighted concerns that many poor countries are net food importers and higher food prices would worsen their trade balances. In this article, we analyze the changes in food trade balances associated with the 32% increase in food prices from 2000/2001 to 2004/2005. We find a small deterioration in food trade balances of low‐income countries and an improvement in middle‐income countries. The deterioration is most severe for countries in conflict and small island states, so attention should be placed first on these countries and on a few very‐low‐income countries that are also vulnerable. Because low‐income countries as a group had much lower agricultural GDP growth rates than middle‐income countries, the answers to food vulnerability in low‐income countries should probably be addressed within the context of incentives for agricultural production.     

Collateral‐free lending with risk‐contingent credit for agricultural development: indemnifying loans against pulse crop price risk in India

This article addresses the problem of collateral‐free lending in the context of agricultural development. We investigate a viable alternative to traditional credit products through the development of risk‐contingent credit for operating loans and farm mortgages and apply the concept to agricultural loans for pulse crops in India. Risk‐contingent credit mitigates business and financial risk by reducing debt obligations depending on the embedded commodity options whose payoffs are linked with commodity price fluctuations. We analyze daily commodity spot prices for pulse crops in India and show how risk‐contingent structured financial instruments can be priced in practice.     

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.     

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.     

Economics of biological control of cassava mealybug in Africa

Pest populations of the cassava mealybug Phenacoccus manihotiMat.‐Ferr. (Homoptera; Pseudococcidae) were reduced successfully by the biological control agent Apoanagyrus (Epidinocarsis) lopezi De Santis (Hymenoptera: Encyrtidae) throughout most of sub‐Saharan Africa. The economics of the project were evaluated based on data from field trials, socio‐economic surveys, published results, and financial information provided by the International Institute of Tropical Agriculture (IITA) and the national programmes. Costs and benefits for the biological control of P. manihoti were calculated over 40 years (1974–2013) for 27 African countries, for four different scenarios, taking into account that impact by A. lopeziand speed of the impact differ between ecological zones. A reasonable calculation considering compounded interest resulted in a benefit cost ratio of about 200 when cassava was costed at world market prices, and of about 370–740 when inter‐African prices were considered.     

Do vouchers improve government fertilizer distribution? Evidence from Nigeria

Government distribution of subsidized fertilizer in Sub‐Saharan Africa is often characterized by cumbersome administrative processes and diversion of the product from the proclaimed beneficiaries. This study uses propensity score matching techniques to analyze an input voucher program in Nigeria that was meant to demonstrate an alternative and more efficient distribution mechanism for subsidized fertilizer. We find that participants in the 2009 voucher program received more bags of subsidized fertilizer than nonparticipants and also paid significantly lower prices compared to those who purchased directly from the market. On average, however, participating in the voucher program did not improve the timeliness of fertilizer receipt or the quality of the product. Where statistically significant, participating in the program increased the likelihood that the product was received late and that some complaint about the product's quality was made. As many developing countries; particularly in Sub‐Saharan Africa adopt the use of input vouchers or scale up already existing programs, this study demonstrates when the distribution of subsidized fertilizer via vouchers improves farmers’ timely access to good and more affordable fertilizer. It highlights some key issues to be considered in order to expand the dimensions of success of well‐targeted input voucher programs