'N NORMATIEWE ONTLEDING VAN DIE VRAAG NA GEELMIELIES IN SUID-AFRIKA / A normative demand analysis of yellow maize in South Africa

Abstract

The demand for yellow maize was analysed using a normative approach. Cost minimizing behaviour of compound feed manufacturers was modelled in a linear programming formulation. The model formulates specific quantities of 14 different poultry-, pig-, cattle-, and sheep rations on a minimum cost basis. A wide variety of local and international feed sources were considered for inclusion in the rations. Prices, the availability and quality of each feed, the inclusion of specific feed sources in a ration and the consumption of each ration could be allowed to vary independently. Price elasticities of demand for yellow maize were estimated after the price of maize was increased parametrically. Substantial differences in maize demand price elasticities for the different livestock enterprises were found. A relaxation of feed importation restrictions showed a significant increase in the price sensitivity of yellow maize and resulted in a decline in the market share of South African yellow maize in the livestock feed market. Policy implications are highlighted. Suggestions for further analyses that are possible via the model are also presented.

Uittreksel

Die vraag na geelmielies word ontleed deur 'n normatiewe benadering te volg. Lineêre programmering is ingespan om die koste minimerende gedrag van veevoersamestellers te modelleer. Die model formuleer spesifieke hoeveelhede van 14 verskillende pluirnvee-, vark-, bees-, en skaaprantsoene op 'n minimumkoste basis. 'n Wye verskydenheid plaaslike sowel as buitelandse voerbronne word oorweeg vir insluiting in die rantsoene. Pryse, die beskikbaarheid en kwaliteit van elk van die voere, die insluiting van spesifieke voerbronne in 'n rantsoen en die verbruik van elke rantsoen kan afsonderlik toegelaat word om te varieer. Pryselastisiteite van die vraag na geelmielies is bereken, nadat die prys van mielies parametries verhoog is. Wesentlike verskille in die pryselastisiteite van vraag wat die verskillende veebedrywe op mielies uitoefen, is bevind. 'n Verslapping in beperkings om invoere vanaf die buiteland in te voer, het 'n beduidende toename in pryssensitiwiteit van geelmielies en 'n afnarne in die markaandeel van Suid-Afrikaanse geelmielies in die veevoermark, tot gevolg. Beleidsirnplikasies word uitgespel. Voorstelle oor verdere ontledings wat met behulp van die model gedoen kan word, word aan die hand gedoen.