International Supply Response

Long-run aggregate agricultural supply elasticities obtained from conventional supply functions fitted to time series data tend to be relatively inelastic in the range of 0.1 to 0.4. I argue that these estimates substantially understate the true long-run supply response in agriculture. Because of the lack of international input price data, implicit output/input price ratios are estimated from a production function assuming profit maximization. The estimation of an aggregate supply function utilizing these price ratios yields long run aggregate supply elasticities in the range of 0.90 to 1.19. These figures are substantially larger than those obtained from conventional supply functions fitted to time series data, but correspond closely to estimates reported in an earlier crosscountry study that used different price data for different points in time. The results imply that policies which distort domestic and/or world market prices of agricultural products cause greater output distortions in both the DCs and LDCs than are predicted by the small supply elasticities obtained from conventional supply estimation.     

An Analysis of U.S. Aggregate Output Response by Farm Size

Past empirical evidence on supply response by size of farm in the U.S.A. provides no clear basis to conclude that supply elasticities vary systematically with farm size. In this paper, the central hypothesis that no systematic relationship exists between production response to price and size of farm is rejected. U.S. farms are disaggregated into nine economic size categories and own-price supply elasticities are measured for per farm and total agricultural output. Empirical results from this study suggest that supply response does vary systematically by farm size, with smaller farms exhibiting greater elasticities than midsized farms.     

CANADIAN WHEAT ACREAGE RESPONSE*

In spite of the criticisms which have been levied against statistical estimation of supply response, it is used in this study to determine the factors causing yearly fluctuations in Canadian wheat acreage. The estimates are derived from 1947–1966 time series data. In formulating price expectations, both the traditional and distributed lag models are used.
It was found that wheat acreage response is not a random process. From a statistical standpoint, wheat and flax prices, wheat stocks on farms, and export sales did affect farmers' wheat acreage decisions. Among the elasticities computed, those for wheat prices were the largest but generally less than one. Barley prices, rainfall prior to seeding, and cattle prices were also considered but did not appear to have a serious influence on wheat acreage.     

Inter‐ and intra‐seasonal crop acreage response to international food prices and implications of volatility

Understanding how producers make decisions to allot acreage among crops and how decisions about land use are affected by changes in prices and their volatility is fundamental for predicting the supply of staple crops and, hence, assessing the global food supply situation. This study makes estimations of monthly (i.e., seasonal) versus annual global acreage response models for the world's principal staple food crops: wheat, corn, soybeans, and rice. Primary emphasis is given to the magnitude and speed of the allocation process. Estimation of intra‐annual acreage elasticity is crucial for expected food supply and for input demand, especially in the light of the recent short‐term volatility in food prices. The econometric results indicate that global crop acreage responds to crop prices and price risks, input costs as well as a time trend. Depending on respective crop, short‐run elasticities are about 0.05 to 0.40; price volatility tends to reduce acreage for some of the crops; comparison of the annual and the monthly acreage response elasticities suggests that acreage adjusts seasonally around the globe to new information and expectations. Given the seasonality of agriculture, time is of an essence for acreage response. The analysis indicates that acreage allocation is more sensitive to prices in the northern hemisphere spring than in winter and the response varies across months.     

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.     

Fertilizer demand in Greece

Limiting fertilizer use is becoming an important policy objective world-wide. However, the debate on appropriate policy measures is far from settled and evidence on fertilizer demand elasticities is still insufficient. Past studies on fertilizer demand leave several methodological and empirical issues open. This paper aims to contribute to the debate on the methodology of estimating fertilizer demand using single-equation methods. Dynamic aspects are also considered using error-correction modelling methodology and cointegration techniques. The model is applied using data front Greece. Short-run and long-run price elasticities of fertilizer demand with respect to own price and to output prices show significant response to price changes and the adjustment coefficient of fertilizer use to the error-correction term was found to be fairly rapid. The main policy conclusion of the paper is that reducing agricultural support may be an alternative and, perhaps, more effective way of reducing fertilizer demand than increasing fertilizer prices.     

Price supply response of vegetable growers in the Sultanate of Oman

Information on supply price elasticities has been acknowledged as being very important for decision makers at the macro and micro levels. This paper presents an empirical investigation of vegetable growers' responses to prices in Oman. It develops a single supply response function incorporating adaptive expectation model for prices. Results indicate that growers adjust relatively fast to changes in expected prices. However, these adjustments tire rather low for some crop in the short-and long-run. Growers' production decisions have also shown a significant response to prices of other products competing for farm space and other production resources. These results will support efforts aimed at market development and crop enhancement programs.     

PRICISM v. STRUCTURALISM IN SUB-SAHARAN AFRICAN AGRICULTURE

A re-examination of data frequently used to support the notion of price discrimination against agriculture in Sub-Saharan Africa suggests that the extent of agricultural taxation has been overstated. In addition, a review of the evidence on the aggregate agricultural supply response to price indicates that elasticities are low, with the most plausible estimates lying in the range 0.2–0.4. Eight structural constraints explaining the poor supply response, to which Sub-Saharan Africa is particularly prone, are identified. Further evidence is presented to show that output responds more significantly to structural factors than to price, and that investment in rural infrastructure will bring about an improved response to price. Capital constraints limit price-induced private investment, so that public sector led investment in new technology and rural infrastructure would appear to be the single most important strategy for reversing the decline in African agriculture.     

Canadian Hog Supply Response: A Provincial Level Analysis

Canada's hog sector has faced two decades of tumultuous growth, yet there are no recent estimates of supply response. This study uses state‐space methods to account for a multiplicity of autonomous structural changes impacting the sector and determines if the fundamental relationship between supply response and hog prices has changed from previous estimates. The results are consistent with prior research but offer the reader previously unavailable estimates of supply response with respect to feed prices and the variability of hog and feed prices. Feed price elasticities are somewhat larger than hog price elasticities. The effects of price risk for supply response appear quite muted but the impacts of feed price risk are greater than for hog price risk.     

AGRICULTURAL PRICE PROTECTION,IMPORT DEPENDENCE AND ECONOMIC DEVELOPMENT: THE CASE OF WHEAT

This article analyses determinants of agricultural price protection for one important food, wheat, in a pooled cross-country and time-series analysis. For the aggregate sample it is shown that wheat price protection increases with a rising level of economic development and with a growing import dependence in wheat. Beyond this general pattern, the paper shows that the variation in wheat price protection can be significantly better explained if qualitative variables are introduced additionally into the model. For example, in Japan, in the Northern European countries and during the commodity price boom (1973–75), wheat price protection followed a specific pattern. Income elasticities and import-dependence elasticities of wheat price protection are computed for all countries in 1968–80, and additionally for various sub-regions and sub-periods.     

Estimation of Area Elasticities from a Standard Profit Function

This article demonstrates that both crop area and output elasticities can be calculated from a profit function. A Chambers/Just profit function (which includes land allocations as quasi-fixed factors) is used to derive shadow price equations for each crop area allocation. Jointly solving these shadow price equations for crop area makes it possible to calculate individual crop area elasticities. A profit function is specified to represent agricultural producers in the state of Iowa. Shadow price equations are jointly estimated with output supply and input demand equations. From these estimated equations, we derive the individual crop area response and output response to a change in prices.     

Implications of the US Farm Bill of 2002 for agricultural trade and trade negotiations

The US Farm Bill of 2002 is the latest in a 7-decade history of farm subsidy laws that transfer funds to farmers and regulate and subsidize production of selected commodities. Fruit, tree nut, ornamental and vegetable crops, hay and meats remain outside scope of main subsidy programs. The new law continues many innovations of the 1996 Act, such as removal of authority for annual land idling and crop price floors accompanied by government stockholding. Government payments remain the primary focus of commodity programs. The total amount of these payments are likely to remain similar to the amount paid in the period 1999–2001, but with some changes in the form of the programs. For example, allowing owners to update acreage and yield payment bases creates additional incentives for farmers to link current planting decisions to anticipated farm subsidies. Similarly, the new program that ties "counter-cyclical" payments to the price of a specific crop also has production stimulus. A new program, estimated to add about 5–10 per cent to marginal milk revenue for smaller farms, makes 'deficiency' payments to dairy farms when milk prices are low. Despite the new programs with added links to stimulating production, new USA programs stimulate production only marginally more than the subsidies of the 1999–2001 period, which were replaced. Furthermore, the USA has flexibility to avoid explicitly violating its WTO commitments. Nonetheless, this US Farm Bill of 2002 has curtailed the previous trends toward lower farm subsidies and smaller production stimuli, and the negative publicity surrounding it has made negotiating reductions of farm trade distortions more difficult.     

Supply response in Ethiopia: accounting for technical inefficiency

Few empirical studies of supply response using the profit function have accounted for technical inefficiency. Using farm‐level panel data from Ethiopia, this study examines the effect of incorporating technical inefficiency in estimating the supply response of peasant farmers. Two systems of output supply and input demand equations are estimated and compared: the conventional model in which technical efficiency is assumed and another in which technical inefficiency is explicitly incorporated. The model with technical inefficiency is preferred on grounds of theoretical consistency and improved estimates, although model comparison tests are not conclusive. Incorporation of inefficiency generally increases the magnitudes and the statistical significance of own price elasticities, substantially so in the case of fertilizer and fertilizer‐intensive crops, and alters the priority attached to nonprice factors. An important result is that only the specification with inefficiency reveals a significant effect of access to extension services on output. Only this specification finds that output increases with household size, which one expects as the farms in the sample are largely subsistence and producing for own consumption. Furthermore, the results demonstrate that farmers' response to incentives is considerably restricted by inefficiency, suggesting that the traditional model would overstate response by excluding the efficiency variable.     

FACTOR MARKET INCIDENCE OF AGRICULTURAL TRADE LIBERALIZATION: SOME ADDITIONAL RESULTS

Liberalization of trade implies changes in producer prices, which has consequences for farm income, agricultural employment and asset values. The relative incidence of the effect of changes in prices on fixed factors depends on the rclative magnitude of the Morishima elasticities of substitution in agricultural production.     

On the Use of Price Ratio in Aggregate Supply Response: Some Evidence from the Poultry Industry

The specification of supply/demand relationships has received considerable attention in agricultural economics (Heien 1977). Economic theory has helped provide a basis for the specification of such relationships, one of its contributions being the proposition that prices should be interpreted only in relative terms. This has had a profound influence on model building in agricultural economics, leading a number of researchers to avoid the use of absolute prices in economic analysis. For this reason, numerous market models of the agricultural economy use price ratios as explanatory variables (e.g., Chen; Chen et al.; Heien, 1976; Gerra; Kulshreshtha and Wilson; Rahn; Talpaz; Morzuck et al.; Houck and Gallagher; Wilson et al.); these examples suggest that the use of such ratios is fairly widespread in econometric modeling of the crop and livestock sectors. One of the best examples of price ratios is the "feed cost to price" ratio commonly used in the analysis of livestock supply response. Indeed, since feed cost constitutes a major part of the total production cost in livestock activities, the "feed cost to price" ratio is often considered a proxy for profitability. For this reason, data on such ratios are regularly published for various livestock activities (e.g., USD A). Also, "feed cost to price" ratios are often employed in the specification of models of livestock supply response, (e.g., Chen; Chen et al.; Heien 1976; Gerra; Kulshreshtha and Wilson; Rahn; Talpaz). However, not all models of aggregate supply response follow this approach. For example, Freebairn and Rausser, and Arzac and Wilkinson, use prices as separate variables rather than in ratio forms in their models. In particular, they do not employ price ratios in their livestock and crop supply equations. The existence of these different approaches raises questions about the appropriateness of the use of price ratios in the modeling of aggregate supply.     

Rural credit and agricultural supply in Brazil

The objective of this study is to determine the financing impact of total expenditure on the use of agriculture inputs (fertilizers, labor, and pesticides), and the output of cotton, rice, beans, corn, soybean, and wheat in Brazil. We study the period 1976–2005. The analysis is based on duality applied to the production theory. The output supplies and conditioned input demands are estimated from a translog multi‐output, multi‐input restricted profit function, where the total production credit is used as proxy of the total expenditure. Farmer expectations with respect to crop prices are incorporated to the estimation based on the quasi‐rational expectation model. The output and input responses to the total expenditure are positive and statistically significant except for cotton, wheat, fertilizer, and pesticides. The short‐run output supply response to own prices is inelastic, except for wheat, which presents elastic response to its price. Acreage has a positive impact on the output supply and it is influenced by land productivity. The main conclusion is that farmers face budget restrictions to purchase inputs, and a government credit program might increase the agricultural supply.     

What Can Acreage Allocations Say about Crop Supply Elasticities? A Convex Programming Approach to Supply Response Disaggregation

This article has two goals. The first is to extend previous results regarding calibration of land‐constrained programming models of agricultural supply against supply elasticities to the general case of multiple constraints. The second goal is to demonstrate how the resulting calibration conditions can be used as a source of identification to disaggregate crop supply elasticities down to the level at which static information on acreage allocations is available. We propose an information‐based disaggregation algorithm to systematically generate regionalised elasticities from a single prior, and provide an empirical illustration.     

The impact of prices and macroeconomic policies on agricultural supply: a synthesis of available results

This paper reviews the literature dealing with the link of agricultural prices and macroeconomic policies to agricultural supply with particular emphasis on Sub-Saharan Africa. Although the study echoes the stylized facts on price elasticities underlined in previous literature reviews, the paper points out that our understanding of the quantitative dimensions of agricultural supply response is weak given the importance of this assumed response for growth, poverty alleviation, and the environment. Indeed, issues such as simultaneity of variables, data pooling, omission of variables, and asymmetry in supply responses to price changes have not been adequately addressed in many instances.     

The supply response of aggregate agricultural output in Jamaica

A dominant theme in the development literature is that individual agricultural products responds to price incentives, not because of shifts Between products, but that total agricultural output is not responsive to price. The econometric evidence tor Jamaica shows that this presumption is not valid. The paper begins by reviewing the growth experience of the Jamaican economy. It then analyzes the trends in agricultural production. The remainder of the paper provides the econometric estimates of broad agricultural output to price. The empirical evidence shows that aggregate agricultural output is responsive to price, but it will take lime for agricultural production to materialize. A summary of the published estimates of the supply response for individual crops is also presented.     

Energy substitutability in transition agriculture: estimates and implications for Hungary

Subsidised energy prices in pre‐transition Hungary had led to excessive energy intensity in the agricultural sector. Transition has resulted in steep input price increases. In this study, Allen and Morishima elasticities of substitution are estimated to study the effects of these price changes on energy use, chemical input use, capital formation and employment. Panel data methods, Generalised Method of Moments (GMM) and instrument exogeneity tests are used to specify and estimate technology and substitution elasticities. Results indicate that indirect price policy may be effective in controlling energy consumption. The sustained increases in energy and chemical input prices have worked together to restrict energy and chemical input use, and the substitutability between energy, capital and labour has prevented the capital shrinkage and agricultural unemployment situations from being worse. The Hungarian push towards lower energy intensity may be best pursued through sustained energy price increases rather than capital subsidies.