Publications > Cahiers (English)> N° 23, 2nd term 1992

• [Product differentiation on sweeteners market : an analysis model], V. Réquillart,
  Éric Giraud-Héraud
• [Agricultural households income assessment : microeconomic approaches],
  J.-L. Brangeon, Guenahaël Jégouzo
• [Substitution in the French feed ingredient sector : the contribution of time series models], Y. Dronne, C. Tavéra
• [The non-market economy and social relations : wood-logging in Ardenne], Agnès Fortier

Différenciation des produits sur le marché des édulcorants : un modèle d'analyse
[Product differentiation on sweeteners market : an analysis model]

V. Réquillart, Éric Giraud-Héraud

In : Cahiers d'Economie et Sociologie Rurales n° 23, 2nd term 1992, pp 5-34

Abstract : The European sweetener market is highly influenced by the regulation. Sucrose market is a reserved one and price and quantities are guaranted. EC prices are higher than world prices and the production of the main competitors of sucrose, namely "high fructose corn syrup (HFCS) produced from cereals, are restricted to about 2 % of the market. In the whole, few European researchers have analysed this competition between sweeteners and its implications for agricultural policy. Smith (1978) analyses the trend of sweeteners markets (sugar from beet and HFCS from cererals) and its implications for economic policy. In particular he shows the differences between the US and EC situations. The author suggests that, even in the EC, a liberalization of HFCS market allows it to take some market share to sugar in particular in countries like Italy where beet production is ill adapted.

The aim of this paper is to characterize the competition between cereal and sugar beet sweeteners. We focus on the imperfect competition on this market with the help of models where the product differentiation is explicitely taking into account (address model of product differentiation à la Hotelling,1929). The consumers program imply a vertical differentiation model where the consumers have different tastes between the offering qualities (following Mussa-Rosen, 1978 and Champsaur-Rochet, 1989). Nevertheless minimising provision costs could imply to use more than one kind of product when starch sweeteners are not sufficiently substituable with the sucrose. We show that microeconomic analysis of consumers and firms behaviours on this specific mark et allows us to throw back into question several of generally accepted ideas based on econometric results of demand in the US market (Lopez and Sepulveda, 1985). In particular, we define a price map characterized by some areas where products benefit in fact of a monopoly power and by others areas where there is effective competition. Simulations on final demand of sweeteners in France and EC are also presented according to different assumptions on regulation and prices (we distinguish ten sectors of consumption). It appears that within small differences of prices, the cereal sweeteners could take over sugar markets for some particular uses such as soft drinks. When sugar prices are about 20 % higher that HFCS prices, substitution in sweeteners could represent a quarter of the total demande in sugar. In comparison with the US market, where HFCS replace about 50 % of sugar, this market for HFCS is rather small. This is mainly due to the differences in the structure of consumption.

Key-words : imperfect competition, vertical differentiation, sweetener, high fructose corn syrup, modelling.

L'estimation du revenu des ménages agricoles : approches microéconomiques
[Agricultural households income assessment : microeconomic approaches]

J.-L. Brangeon, Guenahaël Jégouzo

In : Cahiers d'Economie et Sociologie Rurales n° 23, 2nd term 1992, pp 35-57

Abstract : New forms of state income support for farmers require knowledge of the statistical distribution of farming households according to their total income. However, France has no reliable means of analysing that distribution yet, particularly of low income groups. Realized improvements are very small as we see in revisiting measurement of farmers' personal incomes. Households here considered are those of farmers working exclusively or principally in agriculture. Four sources of microdata are examined : the Farm Accountancy Data Network (RICA in France), tax data, household surveys with interview, other operations such as the "analysis" of Farming Statistics.

RICA is the best tool of agricultural income's measurement for professional farms. With the pluriannual results it is possible to distinguish transient low incomes and persistent low incomes. So we know that if 35 % of holdings belonging to network from 1982 to 1986 (n = 2207) have a negative or zero net income (after payment of compulsory social insurances contributions) during a year at least, more than half of deficits last only one year. If 66 % of holdings have a small net income, i.e. lower than 40 000 F, during one year at least, only 25 % - but it's still much - have such an income during five years. But the lowest area of distribution is partly excluded, smallest holdings being out of survey field. Another restriction is that RICA in France has not for target to capture family incomes from non agricultural origins.

If surveys on fiscal revenues include incomes of all origins, underestimation is important and varying among households. Number of low total incomes is overestimated. However it is the less imperfect source on farmer's non agricultural incomes : wages are better known ; and error margin being less for selected categories of households, these results can be useful to support assumptions on amounts per categories of total fiscal and non fiscal revenues. Although for few years household interview surveys have several questions on incomes, their results on this point for farmers are disappointing.

"Analysis" of farm statistics is an evalution of global income (farm income + other gainful activity return + retirement pension) obtained by families living or working in farms, for selected years. Several of family incomes are calculated by standards. So data are potential incomes at level of each family ; but group's means allow to estimate some disparities. As to implementation of agro-social policy, it refers to personal incomes which usually are roughly estimated. This review leads to specify what partial studies of personal distribution are today possible for farm and non agricultural income of farmers working exclusively or principally in agriculture. Suggestions are made to attempt an improvement of present measurement.

Key-words : France, agricultural income, farming households, incomes, low income, fiscal income, farm accountancy data network.

Substitution dans l'alimentation animale : l'apport des modèles de séries temporelles
[Substitution in the French feed ingredient sector : the contribution of time series models]

Y. Dronne, C. Tavéra

In : Cahiers d'Economie et Sociologie Rurales n° 23, 2nd term 1992, pp 36-86

Abstract : Several papers are aimed at estimating demand relationships for feed inputs for European countries. Many of them use an econometric model derived from the neoclassical theory of the firm and the duality theory. Direct and cross price substitution elasticities for feed ingredients are then estimated under given hypothesis concerning the characteristics of the production function for compound feed.

Such analysis admit three weaknesses :

- First, the whole spectrum of available feed ingredients is generally divided into three to five groups on the basis of an a priori examination of their nutritional content : cereals, protein feed and cereal substitutes for example. The matrix of estimated cross and direct elasticities then highlights the substituability among groups of products. Two justifications can be given. At first, it is necessary to reduce the number of estimable parameters and so the number of estimated equations in order to avoid multi- collinearity problems. Secondly, a translog specification is generally chosen for the production function of the compound feed sector, so that the estimated equations are cost-shares equations which often lead to bad empirical results when some cost-shares are too small. But the dependance of estimated results on the initially retained partition is the real problem because, if cereals can be considered as a relatively homogeneous group, protein rich products and several intermediary products cannot be. Lastly, it is very difficult to estimate substitution elasticities for individual products.

- Second, the identification of just one given econometric model with a priori exclusion and cross-equations restrictions derived from economic theory can hide some characteristics not quite in line with the chosen economic theory.

- Third, many of thoses studies use one period models of the firm. However, provided that the compound feed sector does not make instantaneous adjustments in response to a changing market situation, a dynamic factor demand model would be more convenient. But compared to the vast literature on flexible functional forms, little attention has been given to dynamic models of firm behaviour.

The aim of this paper is to highlight short-run substitution relationships among the main feed ingredients with an alternative method grounded on a vectorial time series model for feed input prices (The model is estimated with French monthly data for the period january 1977 - november 1987). Such a procedure has the advantage not to impose a priori restrictions on the econometric model and the estimated equations are all derived from the information imbedded in the data at hand as usual with time series models. A second advantage lies in the fact that the partition of the various feed ingredients into groups of products is unnecessary : the individual behaviour of each ingredient can be examined. However due to the lack of underlying economic theory, our results are not directly interpretable in terms of classical substitution elasticities. They just act as indicators of the short-run substitution-complementarity relationships among feed ingredients.

Key-words : VAR model, France, time series, animal feed, prices.

Economie non marchande et lien social. L'affouage en Ardenne
[The non-market economy and social relations : wood-logging in Ardenne]

Agnès Fortier

In : Cahiers d'Economie et Sociologie Rurales n° 23, 2nd term 1992, pp 87-108

Abstract : Although it is of course a marginal activity, wood-logging is nonetheless an example, among others, of an economic practice whose underlying logic is alien to the dominant mode of production. An ethnographic survey carried out in the Ardenne region of France in 1984, and repeated in 1986 and 1987, has shown that there has been a revival of this users' right which can be related to the two oil shocks of the 1970s and, at the same time, to the crisis the local metallurgical industry has been undergoing. Although the conjunction of these two phenomena does tend to point to the economic character of this activity, ethnographic observation enables us to put such an interpretation into perspective. The revival of wood-logging has certainly enabled the local population - essentially working class - to make some savings, but above all it has led to the rehabilitation of certain forms of social behaviour that the ideology of technical progress and efficiency has repressed. The principle on which this practice rests is as follows. The wood-loggers cover their own needs in firewood and avoid, inasmuch as this is possible, any monetary transaction ; on the other hand, they encourage self-production, friendly arrangements such as the reciprocal gift system, mutual aid and exchange of services, all of which go well beyond the strict definition of wood-logging. The principle behind these non-monetary forms of exchange, based on the production of use values or, in other words, on the ability to produce goods and services which are intended for exchange, is to stress not the economic value ordinarily attributed to such a good on the market by rather its usefulness. This is a radically different mode of exchange to that which predominates in the capitalist system, inasmuch as it is not the products to be exchanged that are important but the nature of the social relationship between the protagonists on the occasion of the exchange. From this point of view, wood-logging helps to intensify or even to reactivate kinship or friendship relations, as well as generate forms of solidarity between different age groups or between working and workless people. However, this activity, which is physically demanding and as such can be seen as work, differs very clearly form wage labour with no hierarchical constraints nor fixed work time and no need to comply to economic profitability. The wood-logger works as he/she wishes, in the open air, usually trying to combine work with pleasure (by working together with friends or members of the family, with picnics around the camp fire, etc.). Thus, wood-logging undermines the traditional opposition between work and leisure, as it also fudges the borderline between market and non-market activities, between official practices as defined in reference to the laws of the market.

Key-words : non-marketing economy, wood-logging, user's right, gift system, mutual aid, exchange of services, work vs leisure, Ardenne.