Thesis (PhD (Agric))--Stellenbosch University, 2013. / ENGLISH ABSTRACT: It is common practice in computable general equilibrium (CGE) models that the output composition of multi-product industries remains constant despite changes in relative prices of products. The results of any scenario will show that products produced by a single industry will still be produced in the same ratio to each other as reflected by the base data. The objective of the study was to develop a CGE model for South Africa in which this assumption of fixed composition of output can be selectively relaxed. In order to allow industries to adjust their output composition in response to changes in relative prices of products a Constant Elasticity of Transformation (CET) function and the related first order condition were incorporated into an existing CGE model. This alternative specification of an output transformation function in the model enables the modeller to allow selected multi-product industries to increase production of products that show greater price increases relative to other products. The first order condition of the CET function determines the optimal combination of products for each industry. With the inclusion of the CET function there is a trade-off between theoretical rigour of the model and realism of the results, therefore an assumption of input-output separability was introduced as a way of recognising that the inclusion of a CET function violates the assumption that prices in the same row of a social accounting matrix (SAM) are equivalent. The model was calibrated with a SAM for South Africa for 2007 that was developed for purposes of this study. Set controls were included in the model to generalise the model in order that it can be calibrated with data from other countries as well. The SAM for South Africa contains provincial level information in the accounts for agriculture, labour and households. The agricultural industries are defined by geographical area, hence these industries are particularly good examples of multi-product industries that respond to relative price changes when determining production levels of individual products. The adjusted CGE model was used to analyse four scenarios focusing on selected issues mentioned in the National Development Plan for South Africa released by the National Planning Commission in 2011. The scenarios relate to increases in fruit exports as a result of global positioning, technical efficiency improvements for the agricultural sector through continued research and development, factor productivity growth in government and selected services sectors resulting from fighting corruption and curbing strikes, and augmenting the supply of skilled labour through an improvement in the quality of education. The results of the adjusted model show the desired effect: producers produce relatively more of the products for which they can get a relatively higher price and vice versa. This holds true regardless of whether the level of industry output increases or decreases. The impact of the model adjustment and the effects of changes in the levels of elasticities and choice of variables to close the model were analysed as part of the sensitivity analyses. The impact of changes in the functional form, elasticities and model closures on results, are different for each scenario. / AFRIKAANSE OPSOMMING: Dit is erkende praktyk in berekenbare algemene ewewigsmodelle dat die verhoudings waarin produkte tot mekaar geproduseer word deur multi-produk industrieë konstant gehou word, ongeag veranderings in relatiewe pryse van produkte. Die resultate van enige senario sal dus aandui dat die produkte wat deur 'n enkele industrie geproduseer word steeds in dieselfde verhouding tot mekaar geproduseer sal word, soos weerspieël in die basis data. Die doel van die studie was om 'n berekenbare algemene ewewigsmodel vir Suid-Afrika te ontwikkel wat die aanname dat die samestelling van elke industrie se uitset onveranderbaar is, selektief kan verslap. Om toe te laat dat industrieë die samestelling van uitset kan aanpas namate die relatiewe pryse van produkte verander, is 'n Konstante Elastisiteit van Transformasie funksie en die gepaardgaande eerste orde voorwaarde in 'n bestaande berekenbare algemene ewewigsmodel ingesluit. Die eerste orde voorwaarde bepaal die optimale verhoudings waarin produkte geproduseer moet word. Met die insluiting van die Konstante Elastisiteit van Transformasie funksie word teoretiese korrektheid van die model ingeboet in ruil vir meer realistiese resultate, dus is die aanname van inset-uitset onafhanklikheid gemaak en daardeur word ook erken dat as gevolg van die insluiting van die Konstante Elastisiteit van Transformasie funksie word daar nie meer voldoen aan die aanname data alle pryse in dieselfde ry van die sosiale rekeninge matriks (SRM) aan mekaar gelyk is nie. Die model is gekalibreer met 'n SRM vir Suid-Afrika vir 2007 wat vir doeleindes van die studie ontwikkel is. Deur die insluiting van kontroles vir versamelings is die model veralgemeen sodat die model ook met data van ander lande gekalibreer kan word. Die SRM vir Suid-Afrika se rekeninge vir landbou, arbeid en huishoudings bevat inligting op provinsiale vlak. Die landbou industrieë is volgens geografiese gebiede afgebaken en is dus besonder goeie voorbeelde van multi-produk industrieë wat reageer op relatiewe prys veranderings wanneer die produksievlakke van afsonderlike produkte bepaal word. Die aangepaste algemene ewewigsmodel is gebruik om vier senarios te ondersoek wat fokus op geselekteerde onderwerpe vervat in die Nasionale Ontwikkelingsplan wat deur die Nasionale Beplanningskommissie van Suid Afrika in 2011 vrygestel is. Die senarios hou verband met 'n styging in vrugte uitvoere as gevolg van globale posisionering, tegniese produktiwiteitsverhogings vir die landbousektor deur volgehoue navorsing en ontwikkeling, verhoging in die produktiwiteit van produksiefaktore van die regering en geselekteerde dienste sektore deur die aanspreek van korrupsie en vermindering in stakings, en die toename in geskoolde arbeid deur 'n verbetering in die kwaliteit van onderwys. Resultate van die aangepaste model toon die gewenste uitwerking: produsente produseer relatief meer van die produkte waarvoor hulle 'n relatiewe hoër prys kan kry, en omgekeerd. Dit geld ongeag of daar 'n verhoging of 'n verlaging in die vlak van die industrie se uitset is. Die impak van die modelaanpassing, die effek van veranderings in die vlakke van elastisiteite en die keuse van veranderlikes om die model te sluit, is geanaliseer as deel van die sensitiwiteitsanalises. Die impak van veranderings in die funksionele vorm, elastisiteite en modelsluiting op resultate, is verskillend vir elke senario.

Allgemeine Gleichgewichtsmodelle (Computable General Equilibrium (CGE) models) werden oft genutzt, um Erkenntnisse über die gesamtwirtschaftlichen Auswirkungen bildungspolitischer Maßnahmen zu gewinnen. Eine Literaturrecherche zur Integration des Bildungs- und Ausbildungssystems in CGE-Modellen zeigt klare Limitationen bisheriger Studien bezüglich der Darstellung des Bildungs- und Ausbildungssystems und identifiziert damit eine wichtige Forschungslücke, der sich diese Dissertation widmet. Vor diesem Hintergrund ist das Hauptziel dieser Dissertation die Entwicklung eines neuartigen Ansatzes zur Einbeziehung der anerkannten Bildungs- und Berufsbildungssysteme in CGE-Modellen, einschließlich aller potenziellen Verbindungen zwischen diesen beiden Systemen. Das entwickelte Modell ermöglicht die Akkumulation von Arbeitskräften entsprechend der Veränderungen der Anzahl der Absolventen und Schulabbrecher eines integrierten Bildungs- und Ausbildungssystems. Es handelt sich um ein rekursiv-dynamisches Ein-Land-CGE-Modell (STAGE-Edu), das die mittel- bis langfristigen gesamtwirtschaftlichen Effekte verschiedener Bildungs- und Ausbildungspolitiken abbildet. Der Sudan gehört zu den Ländern der unteren mittleren Einkommensklasse, die bezüglich der Förderung der menschlichen Entwicklung vor zahlreichen Herausforderungen stehen. Aus diesem Grund werden in der vorliegenden Dissertation verschiedene bildungspolitische Maßnahmen analysiert und deren Auswirkungen auf das Wirtschaftswachstum und die Humankapitalbildung im Sudan bewertet. Der entwickelte Modellierungsrahmen leistet einen wichtigen Beitrag zur gesamtwirtschaftlichen Darstellung der durch Bildung und Ausbildung bewirkten menschlichen Entwicklung sowie der drauf abzielenden politischen Maßnahmen. STAGE-Edu bietet politischen Entscheidungsträgern ex-ante Erkenntnisse bezüglich der potenziellen Auswirkungen von Maßnahmen zur Verbesserung der Arbeitsqualifikation und letztlich zur Erhöhung des Lebensstandards der Bevölkerung. / Computable General Equilibrium (CGE) models have been widely used to generate insights into the economy-wide implications of education policy measures. A literature review on incorporating the education and training system in CGE models reveals explicit limitations of previous studies depicting vocational education and training system, hence, identifying a significant research gap, which shall be addressed in this dissertation. Against this background, the main objective of this dissertation is to develop a novel approach to incorporate the acknowledged education and vocational training systems in CGE models, including all potential exiting bridges between these two systems. The developed model enables labor force accumulation according to changes in the number of graduates and dropouts from an integrated education and training system. It is a recursive-dynamic single-country CGE model (STAGE-Edu), which depicts the medium- to long-run economy-wide effects of various education and training policies. The Sudan is one of the lower-middle-income countries that face numerous challenges in accelerating human development. For this reason, in the dissertation at hand different education and training policy measures are analyzed and their implications on economic growth and human capital accumulation in the Sudan are assessed. The developed modeling framework contributes to the field of economy-wide depiction of human development triggered by education and training as well as related policy measures. STAGE-Edu provides policymakers with ex-ante insights on potential impacts of measures for enhancing labor skills and ultimately for improving the livelihood of the population.

Questa tesi offre una descrizione dettagliata di come i modelli di equilibrio generale computazionale (CGE) ed i modelli di microsimulazione possano essere utilizzati congiuntamente, partendo dalla letteratura piú recente sull'argomento, e focalizzando l'attenzione in particolare sulla letteratura riguardante i paesi in via di sviluppo. La ragione principale per la quale questi modelli vengono utilizzati congiuntamente risiede nel fatto che il ricercatore vuole essere in grado di studiare contemporaneamente l'eterogeneità degli agenti economici e la complessità della distribuzione del reddito, ed allo stesso tempo di valutare gli effetti macroeconomici delle riforme. Nell'ultimo capitolo costruiamo un modello CGE-microsimulazione per l'economia del Nicaragua. Esso si rivela particolarmente adatto alla riforma di politica economica che vogliamo simulare: l'accordo di libero scambio commerciale tra i paesi dell'America Centrale e gli Stati Uniti è infatti una riforma di tipo macroeconomico, la quale potrebbe tuttavia avere effetti significativi sulla distribuzione del reddito. Con questo modello analizzeremo quindi gli effetti dell'accordo commerciale con gli Stati Uniti sulla distribuzione del reddito in Nicaragua. I risultati dell'analisi registrano soltanto piccole variazioni sia nelle principali variabili macroeconomiche che nella distribuzione del reddito e negli indici di povertà. / This thesis wants to give an assessment and a detailed description of how Computable General Equilibrium (CGE) and microsimulation models can be linked together, taking inspiration from the current literature, with a special focus concerning the literature on developing countries. The main reason why these models are linked together is that the modeller wants to be able to take into account full agents' heterogeneity and the complexity of income distribution, and at the same time to analyse the macroeconomic effects of the policy reforms. In the last chapter, we build a CGE-microsimulation model for the economy of Nicaragua. This model appears to be particularly suited to the policy reform we are willing to simulate with the model: the Free Trade Agreement of Central American countries with USA is mainly a macroeconomic reform, which on the other hand can have important effects on the distribution of income and on poverty. With such a model we will study the possible changes in the distribution of income in Nicaragua deriving from the Free Trade Agreement with USA. Our analysis finds only small changes both in the main macroeconomic variables and in the distribution of income and poverty indices.

At the beginning of the year 2014 carbon tax should be introduced in Czech Republic with the main focus on decreasing CO2 emission from firms not involved in EU ETS. Potential repercussions of this regulatory tool depend on multiple complex events occurring within the economy. In response a macroeconomic general equilibrium model with the base year of 2009 was created. This model is able to identify complex events within the economy and simulate initiation of the tax itself. As a result of this model there is a conclusion that not all sectors will decrease their demand for newly taxed fossil fuels and that an increase of consumption for relatively less taxed fuels for instance natural gas might be expected as a result of the tax initiation. Carbon tax will be according to the simulation results indirectly but significantly influencing the energy sector, which will in spite of the relative cut-price of input fuels respond with decrease in electricity production. Consequent higher electricity price will then cause additional costs for taxed sectors. Important conclusion is also the fact that rational behavior of economic agents could lead to a lower emission reduction than is currently being expected and even further increase in the tax rate beyond 15 EUR/tCO2 would probably not lead to a significant reduction of CO2 emissions.

La scelta del modeller riguardo alla chiusura del modello CGE influenza i suoi risultati finali e le sue prescrizioni di policy. In questa tesi, lo scopo è l’analisi e l’identificazione del problema, sia attraverso una discussione teorica che un’ applicazione pratica. Dall’articolo del 1963 di Amartya Sen in poi, la letteratura ha presentato vari articoli sull’argomento. Attualmente, il problema delle chiusure del modello non appare più centrale nel dibattito. Dopo una breve introduzione su cosa siano i CGE, il loro sviluppo e la loro struttura, è presentata una serie di esemplificative maquette con lo scopo di introdurre al concetto di chiusura, come essa influenzi i risultati e come questa scelta del modeller sia intimamente connessa ai fondamenti macroeconomici del sistema. Dopo la teoria, ci si sposta nel mondo reale analizzando con differenti modelli (Neoclassico, “Bastardo Keynesiano”, Strutturalista/Post- Keynesiano) e diverse chiusure per gli aggregati macroeconomici (risparmi privati, pubblici, e stranieri) l’impatto dell’accordo regionale SADC sull’economia mozambicana. I modelli CGE per il Mozambico sono calibrati su una SAM del 2003 e sono svolti con l’ausilio di GAMS/MPSGE. I risultati dimostrano che la chiusura influenza i risultati stessi del modello per cui ognuno presenta una serie di raccomandazioni politiche per l’applicazione dell’accordo SADC. / Modellers’ choice on closure rules affects a CGE model results and consequently its policy prescriptions. In this thesis, the aim is to detect and assess this issue, both through a theoretical discussion and an empirical application. Starting from Amartya Sen’s 1963 paper, literature presents many contributions on this topic. Currently, the closure rule problem is not central in the CGE debate. After a brief introduction on CGEs, their development and their structure, a series of simple maquette is presented. They have the exemplary role of introducing the concept of closures, explain how they affect final outcomes and how this modeller’s choice is strictly connected to the macroeconomic foundation of the economic system. After theory, we move into the real World analyzing through different models (Neoclassical, “Bastard Keynesian”, and Structuralist/ Post- Keynesian), and through different closure rules for macro- aggregates (private, public and foreign savings) the impact of the Regional Trade Agreement of SADC with respect to the Mozambican economy. The Mozambican CGE models are calibrated on a 2003 Social Accounting Matrix (SAM) and they are performed using GAMS/ MPSGE. Outcomes show that closure rules affect them and each model presents a set of policy prescription to implement the SADC agreement.