Climate change and household welfare in sub-Saharan Africa: empirical evidence from Swaziland

The fifth assessment report of the Intergovernmental Panel on Climate Change and several studies suggest that climate change is expected to increase food insecurity and poverty in many parts of the world. In this paper, we adopt a microeconometric approach to empirically estimate the impact of climate change-induced hikes in cereal prices on household welfare in Swaziland (also Kingdom of Eswatini). We do so first by econometrically estimating expenditure and price elasticities of five food groups consumed by households in Swaziland using the Almost Ideal Demand System (AIDS), based on data from the 2009/2010 Swaziland Household Income and Expenditure Survey. Second, we use the estimated expenditure and compensated elasticities from the AIDS model, food shares from the household survey, and food price projections developed by the International Food Policy Research Institute (IFPRI) to estimate the proportionate increase in income required to maintain the level of household utility that would have prevailed absent an increase in food prices. Our results show increases in cereal prices due to climate change are expected to double extreme poverty in urban areas and increase poverty in rural areas of the country to staggering levels - between 71 and 75%, compared to 63% before the price changes. Income transfers of between 17.5 and 25.4% of pre-change expenditures are needed to avoid the welfare losses.