Jooste, A.Ogundeji, Abiodun Akintunde2015-10-122015-10-122007-11http://hdl.handle.net/11660/1364English: The economic evaluation of, for example, trade liberalisation requires complex models that can take different forms and which are based on economic theory. Of particular importance in partial and general equilibrium models is the behavioural function that governs the interactions between different variables. For example, in these models changes in trade regimes and tariffs alter the domestic price of imported goods relative to that of domestically produced goods, and such changes in relative prices affect the fraction of the demand supplied by imports. If such behaviour is not modelled correctly, trade impacts can be either under- or overestimated. Estimates of the elasticity of substitution between goods differentiated by their place of origin are therefore required. A review of the literature revealed that estimates of Armington elasticities are not available for agricultural products in the majority of countries, including South Africa, in spite of the importance of including Armington elasticities when evaluating the impact of trade policies. The focus of this study was on the estimation of Armington elasticities for selected agricultural products in South Africa. In this study, non-nested CES Armington elasticities were estimated using the econometric approach for the following agricultural products: Meat of bovine animals (fresh or chilled); meat of bovine animals (frozen); meat of swine (fresh, chilled or frozen); maize or corn; wheat and meslin; soybeans (broken or not broken); and sunflower seeds (broken or not broken). Three econometric models, namely geometric lag, single-equation error correction, and ordinary least square, were estimated based on the time series properties of the data. All the products considered in this study have significant Armington elasticities at 10 percent level of significance. All the products except soybeans have short and long-run elasticities. The estimates of Armington elasticities range between 0.60 and 3.31 for the short-run elasticities, and between 0.73 and 3.21 for the long-run elasticities. These values suggest that imported and domestic agricultural products are not perfect substitutes. The long-run elasticity estimates show that meat of bovine animals (frozen) is the most import sensitive product followed by maize, meat of bovine animals (fresh or chilled) and sunflower seeds, while wheat and meat of swine (fresh, chilled or frozen) are the least import-sensitive products. The short-run elasticities show that soybeans is the most import-sensitive product followed by meat of bovine animals (fresh or chilled), while meat of swine (fresh, chilled or frozen) is the least import-sensitive product. The dummy variables representing seasonality were found to be statistically not significant for livestock products, with the exception of the fourth quarter for meat of swine (fresh, chilled or frozen). However, dummy variables for the grain products were statistically significant. The results show that seasonality is an important factor in determining import demand for grain products. Dummy variables included to control for outliers were not significant, nor was the dummy variable included for trade liberalisation. The value of this study is that the estimated Armington elasticities will allow researchers to evaluate more precisely the economic impacts of trade liberalisation and changes in tariffs, as well as other trade policies, in partial and general equilibrium models that include South African agriculture.Afrikaans: Die ekonomiese evaluering van byvoorbeeld, handelsliberalisering, vereis komplekse modelle, gegrond op ekonomiese teorie, wat verskillende vorms kan aanneem. Wat veral belangrik is in gedeeltelike, sowel as algemene ewewigsmodelle, is die parameters wat die interaksie tussen verskillende veranderlikes beheer. In hierdie modelle byvoorbeeld, het veranderings in handelstelsels en –tariewe ‘n impak op die binnelandse prys van ingevoerde goedere relatief tot die pryse van goedere wat plaaslik geproduseer is. Sodanige veranderings in relatiewe pryse beïnvloed daardié gedeelte van die plaaslike vraag wat ingevoer word. Indien sodanige gedrag nie korrek gemodelleer word nie, kan handelsimpakte oor- of onderskat word. Die elastisiteit van substitusie tussen goedere wat volgens hulle oorsprong bepaal word, moet dus beraam word. Ten spyte daarvan dat dit uiters belangrik is om die Armington elastisiteit in berekening te bring wanneer die impak van handelsbeleid geëvalueer word, het ‘n oorsig van die literatuur aan die lig gebring dat beramings van die Armington elastisiteit in die meeste lande, insluitend Suid-Afrika, nie geredelik ten opsigte van landbouprodukte beskikbaar is nie. In hierdie studie is daar gefokus op die beraming van die Armington se elastisiteit vir geselekteerde landbouprodukte in Suid-Afrika. In die studie is daar ‘n beraming gedoen van die “non-nested CES” Armington elastisiteit deur gebruik te maak van die ekonometriese berekenings ten opsigte van die volgende landbouprodukte: beesvleis (vars of verkoel), beesvleis (gevries), varkvleis (vars, verkoel of gevries), mielies of graan, koring en meslin, sojabone (gebreek of v ongebreek) en sonneblomsaad (gebreek of ongebreek). Drie ekonometriese modelle, naamlik “geometric lag”, “single-equation error correction”, en die “ordinary least square”, is beraam op grond van die tydreekseienskappe van die data. Al die produkte wat in hierdie studie oorweeg is, beskik oor betekenisvolle Armington elastisiteite op ‘n 10 persent vlak van betekenisvolheid. Behalwe vir sojabone, beskik al die produkte oor kort- en langtermyn elastisiteite. Die beraming van die Armington elastisiteite wissel tussen 0.60 en 3.31 vir die korttermyn elastisiteite en tussen 0.73 en 3.21 vir die langtermyn elastisiteite. Sodanige waardes dui daarop dat ingevoerde en plaaslike landbouprodukte nie perfekte plaasvervangers is nie. Die langtermyn elastisiteit-beramings toon dat beesvleis (gevries) baie invoer-sensitief is, gevolg deur mielies, beesvleis (vars of verkoel) en sonneblomsaad, terwyl koring en varkvleis (vars, verkoel of gevries) die minste sensitiwiteit vir invoere toon. Die korttermyn elastisiteite dui daarop dat sojabone die meeste sensitiwiteit teenoor invoere toon, gevolg deur beesvleis (vars of verkoel), terwyl varkvleis (vars, verkoel of gevries) die minste invoersensitief is. Daar is bevind dat, met die uitsondering van die vierde kwartaal vir varkvleis (vars, verkoel of gevries), die veranderlikes wat seisoensgebondenheid verteenwoordig, geen statistiese betekenis inhou vir lewendehawe produkte nie. Seisoensgebondenheid veranderlikes vir graanprodukte was egter statisties betekenisvol. Die resultate toon dat seisoensgebondenheid ’n belangrike faktor is in die bepaling van invoer-aanvraag vir graanprodukte. Veranderlikes wat ingesluit is om uitskieters in die data te verteenwoordig was nie betekenisvol nie en ook nie veranderlikes vir handelsliberalisering nie. Die waarde van hierdie studie lê daarin dat die geraamde Armington elastisiteite navorsers in staat sal stel om meer akkuraat te bepaal wat die ekonomiese impak sal wees van handelsliberalisering en veranderings in tariewe, sowel as ander handelsbeleidsrigtings in gedeeltelike en algemene ewewigsmodelle wat landbou in Suid-Afrika insluit.enArmington elasticityImport substitutionTrade liberalisationTrade policy modelsBehavioural parametersElasticity (Economics)International trade -- Econometric modelsProduce trade -- South AfricaCommercial policy -- Econometric modelsAgriculture -- Economic aspects -- South AfricaDissertation (M.Sc.Agric. (Agricultural Economics))--University of the Free State, 2007DissertationUniversity of the Free State