Deriving a Global Social Accounting Matrix from GTAP version 5 Data

This paper reports a method for converting version 5 of the GTAP database into a global SAM that is stored in GAMS data exchange (GDX) format or in a Header Array (HAR) format. The focus of attention is on the generation of a SAM representation of the GTAP database that is fully consistent with the GTAP model; as such the resultant SAM can be readily used to calibrate a version of the GTAP model that had been coded in GAMS. The GAMS code used to generate the SAM representation of the GTAP database is provided as a GAMS model library – this code has been tested with versions 5.0 and 5.3 of the GTAP database

Impact of Switching Production to Bioenergy Crops: The Switchgrass Example January 2005

This paper reports the results of a series of simulations that evaluate the general equilibrium effects of substituting crude oil by biomass, specifically switchgrass, in the production of petroleum in the USA. The simulations are inspired by debates over the implications for developing countries if agricultural policies in the USA are changed so that agricultural land is transferred from the production of cereals and other crops to biomass production. The results confirm expectations that such a policy shift would raise cereal and other agricultural prices, due to a general reduction in food production in the USA. However, the reduction in the demand for crude oil in the USA causes terms of trade effects that more than offset any potential benefits for developing countries due to the depreciation of their exchange rates, causing a general decline in economic welfare. Moreover, the declines in welfare are proportionately greater for developing countries due to their small levels of production of the commodities whose prices increase with the change in USA agricultural production

A SAM Based Global CGE Model using GTAP Data January 2005

This paper provides a technical description of a global computable general equilibrium (CGE) model that is calibrated from a Social Accounting Matrix (SAM) representation of the Global Trade Analysis Project (GTAP) database. A distinctive feature of the model is the treatment of nominal and real exchange rates and hence the specification of multiple numéraire

Tax policy to reduce carbon emissions in south Africa

Noting that South Africa may be one of the few African countries that could contribute to mitigating climate change, the authors explore the impact of a carbon tax relative to alternative energy taxes on economic welfare. Using a disaggregate general-equilibrium model of the South African economy, they capture the structural characteristics of the energy sector, linking a supply mix that is heavily skewed toward coal to energy use by different sectors and hence their carbon content. The authors consider a"pure"carbon tax as well as various proxy taxes such as those on energy or energy-intensive sectors like transport and basic metals, all of which achieve the same level of carbon reduction. In general, the more targeted the tax to carbon emissions, the better the welfare results. If a carbon tax is feasible, it will have the least marginal cost of abatement by a substantial amount when compared to alternative tax instruments. If a carbon tax is not feasible, a sales tax on energy inputs is the next best option. Moreover, labor market distortions such as labor market segmentation or unemployment will likely dominate the welfare and equity implications of a carbon tax for South Africa. This being the case, if South Africa were able to remove some of the distortions in the labor market, the cost of carbon taxation would be negligible. In short, the discussion of carbon taxation in South Africa can focus on considerations other than the economic welfare costs, which are likely to be quite low.Environmental Economics&Policies,Transport Economics Policy&Planning,Taxation&Subsidies,Energy Production and Transportation,Environment and Energy Efficiency

An Analysis of South Africa's Value Added Tax

In this paper, the authors describe South Africa's value added tax (VAT), showing that (1) the VAT is mildly regressive, and (2) it is an effective source of government revenue, compared with other tax instruments in South Africa. They evaluate the VAT in the context of other distortions in the economy by computing the marginal cost of funds-the effect of raising government revenue by increasing the VAT rates on household welfare. Then they evaluate alternative, revenue-neutral tax systems in which they reduce the VAT and raise income taxes. For the analysis, the authors use a computable general equilibrium (CGE) model with detailed specification of South Africa's tax system. Households are disaggregated into income deciles. They demonstrate that alternative tax structures can benefit low-income households without placing excess burdens on high-income households.

Aid, growth, and real exchange rate dynamics

Devarajan, Go, Page, Robinson, and Thierfelder argued that if aid is about the future and recipients are able to plan consumption and investment decisions optimally over time, then the potential problem of an aid-induced appreciation of the real exchange rate (Dutch disease) does not occur. In their paper,"Aid, Growth and Real Exchange Rate Dynamics,"this key result is derived without requiring extreme assumptions or additional productivity story. The economic framework is a standard neoclassical growth model, based on the familiar Salter-Swan characterization of an open economy, with full dynamic savings and investment decisions. It does require that the model is fully dynamic in both savings and investment decisions. An important assumption is that aid should be predictable for intertemporal smoothing to take place. If aid volatility forces recipients to be constrained and myopic, Dutch disease problems become an issue.Economic Theory&Research,Debt Markets,Currencies and Exchange Rates,Emerging Markets,

Wage subsidy and labor market flexibility in south Africa

In this paper, the authors use a highly disaggregate general equilibrium model to analyze the feasibility of a wage subsidy to unskilled workers in South Africa, isolating and estimating its potential employment effects and fiscal cost. They capture the structural characteristics of the labor market with several labor categories and substitution possibilities, linking the economy-wide results on relative prices, wages, and employment to a micro-simulation model with occupational choice probabilities in order to investigate the poverty and distributional consequences of the policy. The impact of a wage subsidy on employment, poverty, and inequality in South Africa depends greatly on the elasticities of substitution of factors of production, being very minimal if unskilled and skilled labor are complements in production. The desired results are attainable only if there is sufficient flexibility in the labor market. Although the impact in a low case scenario can be improved by supporting policies that relax the skill constraint and increase the production capacity of the economy especially towards labor-intensive sectors, the gains from a wage subsidy are still modest if the labor market remains very rigid.Labor Markets,Labor Policies,,Economic Theory&Research,Access to Finance

Wage Subsidy and Labour Market Flexibility in South Africa Delfin S. Go, Marna Kearney, Vijdan Korman, Sherman Robinson and Karen Thierfelder

In this paper, we use a highly disaggregate general equilibrium model to analyse the feasibility of a wage subsidy to unskilled workers in South Africa, isolating and estimating its potential employment effects and fiscal cost. We capture the structural characteristics of the labour market with several labour categories and substitution possibilities, linking the economy-wide results on relative prices, wages, and employment to a micro-simulation model with occupational choice probabilities in order to investigate the poverty and distributional consequences of the policy. The impact of a wage subsidy on employment, poverty, and inequality in South Africa depends greatly on the elasticities of substitution of factors of production, being very minimal if unskilled and skilled labour are complements in production. The desired results are attainable only if there is sufficient flexibility in the labour market. Although the impact in a low case scenario can be improved by supporting policies that relax the skill constraint and increase the production capacity of the economy especially towards labour-intensive sectors, the gains from a wage subsidy are still modest if the labor market remains very rigid.

Economy-wide and distributional impacts of an oil price shock on the south African economy

As crude oil prices reach new highs, there is renewed concern about how external shocks will affect growth and poverty in developing countries. This paper describes a macro-micro framework for examining the structural and distributional consequences of a significant external shock-an increase in the world price of oil-on the South African economy. The authors merge results from a highly disaggregative computable general equilibrium model and a micro-simulation analysis of earnings and occupational choice based on socio-demographic characteristics of the household. The model provides changes in employment, wages, and prices that are used in the micro-simulation. The analysis finds that a 125 percent increase in the price of crude oil and refined petroleum reduces employment and GDP by approximately 2 percent, and reduces household consumption by approximately 7 percent. The oil price shock tends to increase the disparity between rich and poor. The adverse impact of the oil price shock is felt by the poorer segment of the formal labor market in the form of declining wages and increased unemployment. Unemployment hits mostly low and medium-skilled workers in the services sector. High-skilled households, on average, gain from the oil price shock. Their income rises and their spending basket is less skewed toward food and other goods that are most affected by changes in oil prices.Economic Theory&Research,,Labor Policies,Markets and Market Access,Access to Finance

Bridging the disciplinary gap in conservation agriculture research, in Malawi. A review

Conservation Agriculture has emerged as a popular form of climate smart agriculture aimed at enhancing climate change resilience for smallholder farmers across Africa. Despite positive biophysical results, adoption rates remain low. It has been acknowledged that improved understanding of farmer decision-making is needed due to the variation in socio-economic and agro-ecological contexts which drives the research agenda to answer the question ‘what forms of Conservation Agriculture work, where, and why?’. To fully understand this question, we need to approach the study of Conservation Agriculture within complex farming systems by collating and integrating different forms of knowledge. In this paper, we discuss (1) a comparison of disciplinary approaches to evaluating Conservation Agriculture in Malawi, (2) the identification of the knowledge gaps that persist at the intersection of these disciplines and (3) recommendations for alternative and interdisciplinary approaches in addressing these knowledge gaps. With a focus on published studies from Malawi, we show that the Conservation Agriculture literature represents two distinct approaches to addressing the question ‘what forms of Conservation Agriculture work, where, and why?’, namely agro-ecological and socio-economic and that neither of these approaches can address the full scope of this question, in particular its ‘why’ component. To overcome these challenges, there is a need for access to compatible, comprehensive data sets, methodological approaches including farmer participation and ethnography, through on-farm trial research as a middle ground between disciplinary approaches