Threshold Cointegration in the Greek Milk Market

This article investigates the nonlinear adjustment between consumer and producer prices in the Greek milk sector using a threshold error correction autoregressive model. The results reject the null hypothesis of linear cointegration in favor of a 2-regime threshold cointegration model. A cointegrating relationship is expected only when equilibrium consumer price is decreased more than 24.12% or the equilibrium relative markup is squeezed more than 62.74%. In this case consumer prices have to increase faster than producer prices to restore the long-run equilibrium between consumer-producer milk prices.     

Supermarket Promotions and Food Prices: A Note

Using a sample comprising nearly 250,000 weekly prices from the largest seven UK supermarket chains, this note investigates two pricing practices that have attracted public interest: the tendency for promotions to ‘disguise’ rises in non‐sale prices and the inflation of prices prior to sales which ‘exaggerate’ the discount. Analysing price dynamics before and after periods of promotional discounting results show post‐sale prices are typically lower than pre‐sale prices, contrary to the disguise hypothesis. We do, however, find evidence of exaggeration of the discount, which may potentially explain why prices fall after discounts, although the evidence is not sufficiently widespread for this to be the sole cause. Results parallel the competition authority's view of supermarket promotions and point to the useful contribution that retail price microdata might play in keeping prices in check in countries where highly concentrated retail sectors raise similar concerns.     

Examining long-run relationships between Australian beef prices

Cointegration and impulse response analyses are used to investigate the short-run and long-run dynamics of the Australian beef market. The aim of this study is to determine whether long-run relationships existed between Australian beef prices at the farm, wholesale and retail levels. Based on monthly data from 1971 to 1994, the results show that all three prices considered are cointegrated. Furthermore, the wholesale price is found to be weakly exogenous. The latter result might be an indication of market inefficiency due in part to price levelling often practised in the beef marketing system.     

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.     

Estimation of dynamic maize supply response in Zambia

Increased attention on government pricing policies among African nations leads directly to a need for information about producer responses to price adjustments. This is especially true in the case of Zambian maize production. Maize is the most important crop grown in Zambia. It accounts for more than 80% of the value of marketed food crops, is heavily relied on for subsistence consumption, and is a staple food in the diet of all Zambian citizens. This paper analyzes the aggregate price response of maize supply in Zambia using a dynamic regression analysis. As a result, short, intermediate and long-run multipliers/elasticities are measured which can be used to analyze the effect of future price policy changes. It was found that a second-order rational distributed lag model best fits the available data. Estimates of short-run elasticities of supply for maize and fertilizer prices are 0.54 and –0.48, respectively. The corresponding estimated long-run elasticities are 1.57 and – 1.44.     

Dynamics of rice prices and agricultural wages in the Philippines

Rice trade liberalization in the Philippines should decrease domestic rice prices impacting both agricultural wages and the welfare of agricultural wage earners. This study examines the short-run and long-run relationship between rice prices and agricultural wages in the Philippines using a neoclassical wage determination model. Three empirical frameworks are used—a cointegration/error correction framework, which assumes nonstationary variables in long-run equilibrium, a first difference model that assumes nonstationary variables but no long-run equilibrium, and an OLS framework that assumes the model variables are stationary. Conclusions are reasonably robust across the three empirical frameworks with wages adjusting positively to rice price changes with a short-run elasticity of 0.29 to 0.57, and a long-run elasticity of 0.70 to 1.0 in preferred models. An analysis of welfare implications suggests that although households that are heavily reliant on agricultural wages for income will be adversely affected by rice price decreases, other households will benefit.     

SUPPLY RESPONSES IN THE SOUTH AUSTRALIAN POTATO INDUSTRY

The potato industry in South Australia is characterised by very unstable prices. One hypothesis for this instability is that potato growers' acreage responses follow a cobweb pattern, that is, a one year lag of acreage to price. This hypothesis is tested, together with a two year lag and a distributed lag. The distributed lag model seems the most satisfactory and gives a short-run elasticity of acreage to price of 0.36 and a long-run elasticity of 1.09. An alternative to the lagged price hypothesis is the "constant cash return" hypothesis which postulates that potatoes are grown to provide a certain cash income to permit farm development. This explanation of acreage response only seems relevant in the dairying and fat lamb areas of the State.     

The Contingent Tariff of the Special Safeguard Mechanism: What Happens When Markets are Imperfectly Competitive?

Contingent tariffs for agri‐food commodities have been proposed as a Special Safeguard Mechanism (SSM) in the Doha Round negotiations by the G33 group of countries as an instrument to control downward spikes in their border prices and/or surges of imports. The objective is to safeguard the livelihood security of farm households in poor countries. To date, most analysis of such tariffs uses stochastic partial equilibrium models with perfect competition. Yet in many markets for such commodities, imperfectly competitive market intermediaries play an important role in determining producers' prices, as do state trading enterprises (STEs). A stochastic partial equilibrium model of a typical importing country situation is specified in which there are either imperfectly competitive domestic intermediaries with a contingent tariff or an STE. The role of these intermediaries in influencing price behaviour and livelihood security in the presence of contingent tariffs alters the conclusion based on models of perfect competition. Using Monte‐Carlo simulation, it is shown that the efficacy of a contingent tariff is substantially reduced as the number of firms declines because increasingly they absorb the tariff, and the procurement price and producer surplus do not increase to the extent that they do under perfect competition.     

Local polynomial fitting and spatial price relationships: price transmission in EU pork markets

We study price transmission processes within EU pork marketsafter the implementation of the EU single market in 1993. Wecompare results derived from non-parametric regressions withthose obtained using alternative non-linear threshold models.Both techniques support the hypothesis that prices are transmittedacross spatially separate EU pig markets and provide evidencefor asymmetric price adjustments. They also suggest the existenceof a range of price differentials where equilibrating priceadjustments are less intense. Non-parametric techniques oftensuggest a higher degree of price transmission than that impliedby threshold models.     

A SIMULATION APPROACH TO THE ANALYSIS OF STABILISATION POLICIES IN AGRICULTURAL MARKETS: A CASE STUDY*

Agricultural markets are very often susceptible to year-to-year fluctuations in price and output and it is generally agreed that it would be desirable to control these fluctuations by intelligent market support operations. In this paper we develop a simulation model to assess the efficacy of market support operations in the case of egg market in the U.K. during the period 1958-68. We argue that for this problem a simulation approach is more effective than either a geometric or an algebraic approach. On the basis of our analysis, we find that in the absence of the market support operations of the British Egg Marketing Board during the period 1958-68, the long-run average return to the egg producer would have been only marginally different from the actual but the instability of the market would have been substantially greater. We also found that because of the nature of the subsidy arrangements, there were severe limits to the Egg Board's capacity to increase producer price even in the short run in spite of the inelastic demand curve. More generally, we conclude that marketing Boards in situations similar to the Egg Board's should aim at keeping close to the long-run producer price rather than short-run profit maximisation.     

Value‐Chains in the Andes: Upgrading for Ecuador's Blackberry Producers

We apply a value chain approach to examine how blackberry producers in Ecuador can improve production and marketing practices to obtain more favorable prices. Results show that general upgrading actions are associated with improved producer prices, and specific activities, such as seeking information from reputable sources can lead to substantial welfare improvements. The paper goes beyond most value chain studies which treat participation in a ‘modern’ value chain as a discrete state. Ecuador's blackberry industry is evolving incrementally with no clearly discernible ‘modern’ market chains. Instead, producers incrementally make improvements in multiple dimensions. Relatively low‐cost practices, many of which do not imply substantial risk or investment, are associated with price improvements. Obstacles to participation in incremental value chain upgrading activities are not insurmountable. In particular, scale of production is not a limiting factor: small‐scale producers are not precluded from adopting improved practices and they do not suffer in terms of price received.     

Impacts of the End of the Coffee Export Quota System on International‐to‐Retail Price Transmission

We examine the impact of the end of the coffee export quota system (EQS) on international‐to‐retail price transmission in France, Germany and the United States. We take account of the existence of long‐run threshold effects and short‐run price transmission asymmetries (PTAs). We find evidence of threshold effects in both periods (EQS and post‐EQS) in all three countries and the presence of short‐run PTAs during the post‐EQS period in all countries, but not during the EQS period. Our results indicate that the threshold values are smaller in the post‐EQS period, suggesting that retail prices became more responsive to changes in international prices. However, the speed of adjustment towards the long‐run equilibrium decreases during the post‐EQS period in the three countries. In the short run, non‐linear impulse response analyses indicate that a shock in international prices was more persistent during the EQS period than in the post‐EQS period. Moreover, we find evidence of short‐run PTAs in the post‐EQS period, with differences across countries. We find support for the ‘rockets and feathers’ principle in the United States; in contrast, retail prices respond faster when international prices are falling in Germany and France. We explain these differences in terms of market structures.     

Marketing margins and price transmission on the Hungarian beef market

There is a wealth of literature on farm-retail price spread for different commodities and countries. However, research on price transmission and marketing margins in the transition economies is still limited. The paper analyses two specific aspects of transition: the larger probability of asymmetric price transmission and structural changes in the case of Hungarian beef chain. The article identifies the date of structural break applying the Gregory and Hansen procedure with recursively estimated breakpoints and ADF statistics. Exogeneity tests reveal the causality runs from producer to retail prices. Homogeneity is rejected, suggesting a mark-up pricing strategy. Price transmission analysis suggests that, despite the common belief, price transmission on the Hungarian beef meat market is symmetric on both long and short run.     

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.     

Information-rich wheat markets in the early days of COVID-19

This paper uses the information implicit in commodity futures and options prices to infer market beliefs about the impact of early-stages COVID-19 on commodity market fundamentals. The particular commodity examined is soft red winter (SRW) wheat, and the timeframe is early February to late March 2020. The analysis highlights various adjustments in the cash and futures price of SRW wheat in light of surging short-run demand from consumer hoarding of staple food products, and a weakening long-run market from growing wheat stocks and an emerging global recession. This split is causing the forward curve to flatten and basis levels to invert. The change over time in the price of options on wheat futures reveals increased price volatility in response to growing uncertainty about the COVID-19 impacts. Similarly, changes in the skewness of the option's volatility smile illustrate a shift in traders’ perception about risk in the right versus left tail of the price distribution.     

Equilibrium Analysis of a Quota-regulated Market

Existing micro economic studies of quota-regulated markets have emphasized the short-run effects of market disturbances. This paper considers the long-run market equilibrium impacts of changes in technology, in input prices and in the distribution of output price when risk averse firms may freely enter and exit the regulated industry. Some of the results are intuitive, while others are not. In general, signing long-run equilibrium results requires a less restrictive preference structure than does signing short-run results. However, the nature of the equilibrating mechanism, ignored in partial analysis, is found to be important.     

Decomposing changes in agricultural price gaps: an application to Russia

The article develops a method for decomposing changes in agricultural price gaps, defined as the difference between a commodity's domestic producer and border prices. We use OECD's procedure for decomposing changes in the market price support part of producer support estimates as the starting point for our decomposition method, and our method provides a basis for critiquing OECD's decomposition approach. The transmission of changes in border prices (world prices and the exchange rate) to domestic prices is a key element in the decomposition. The method is demonstrated using Russian agricultural price gaps. The results support the argument that for Russian agriculture during the transition period, the main cause of changes in price gaps has been incomplete transmission of changes in the exchange rate to domestic prices, and where the weak transmission results mainly not from policy intervention, but rather from deficient market conditions, in particular poor market infrastructure. The policy implication is that underdeveloped infrastructure has strongly limited the benefits to the Russian economy from agricultural trade liberalization.     

The price stabilization effects of the EU entry price scheme for fruit and vegetables

The article assesses the stabilization effects of the EU import regime for fresh fruit and vegetables based on the entry price system (EPS). The analysis is carried out on the EU prices of tomatoes and lemons and those of imports from some of the main competing countries on the EU domestic markets: Morocco, Argentina, and Turkey. It is based on the estimation of a threshold vector autoregressive econometric model that is shown capable of taking the workings of the import regime into account. The model shows that prices behave differently when import prices are above/below the trigger entry price. This article allowed to highlight the cases for which the isolation effect of EPS seems reached and the resulting stabilization effects.     

The Determination of Agricultural Wage Rates in Bangladesh

The impact of the ‘green revolution’ on wages has been a contentious issue. This paper uses the cointegration and error correction approach to identify long and short-run relationships between prices, agricultural production and wages of agricultural labourers in Bangladesh, test for homogeneity, test for weak exogeneity with the Johansen-Juselius methodology, test for a structural break, and estimate the long and short-run elasticities of nominal wages with respect to rice prices. We find that agricultural wages have strong positive long run relationships with rice prices, manufacturing wages and agricultural productivity. The short run response of wages, estimated consistently with these longer run relationships, to rice prices is small, highlighting the vulnerability of the rural poor to sudden rises in rice prices, even though in the longer run nominal wages respond sufficiently to rice prices. Policy can promote growth of agriculture and manufacturing but should also mitigate the short run food insecurity of agricultural labourers.     

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.