Upgrading irrigation infrastructure in the Murray Darling Basin: is it worth it?
Infrastructure upgrades appear superficially to be a politically acceptable way of increasing environmental flows in the Murray-Darling Basin. From an economic perspective, their costs and benefits should be compared with other policy instruments. We do so using TERM-H2O, a dynamic regional CGE model with considerable basin detail. Voluntary and fully compensated buybacks are much less costly than upgrades as a means of obtaining a target volume of environmental water. Even during drought, when highly secure water created by infrastructure upgrades is more valuable, the upgrades remain too costly. As an instrument of regional economic management, infrastructure upgrades are inferior to public spending on health, education and other services in the basin. For each job created from upgrades, the money spent on services could create between three and four jobs in the basin.
Modelling Drought and Recovery in the Southern Murray‐Darling Basin
The prolonged drought from 2006–07 to 2008–09 in south-eastern Australia presented severe difficulties for dry-land and irrigation farmers in the southern Murray-Darling basin. A dynamic multi-regional computable general equilibrium model (TERMH2O) is used to estimate the economy-wide small region impacts during and after drought. Drought reduces real GDP in some small regions by up to 20 per cent. Irrigation water trading and farm factor movements alleviate losses. The drought results in an estimated 6000 jobs being lost across the southern basin. Depressed farm investment during drought results in farm capital not returning to baseline levels after drought. Consequently, job numbers in 2017–18 remain 1500 below forecast in the southern basin.
The economic costs of extreme weather events: a hydrometeorological CGE analysis for Malawi
ABSTRACT Extreme weather events such as droughts and floods have potentially damaging implications for developing countries. Previous studies have estimated economic losses during hypothetical or single historical events, and have relied on historical production data rather than explicitly modeling climate. However, effective mitigation strategies require knowledge of the full distribution of weather events and their isolated effects on economic outcomes. We combine stochastic hydrometeorological crop-loss models with a regionalized computable general equilibrium model to estimate losses for the full distribution of possible weather events in Malawi. Results indicate that, based on repeated sampling from historical events, at least 1.7 per cent of Malawi's gross domestic product (GDP) is lost each year due to the combined effects of droughts and floods. Smaller-scale farmers in the southern region of the country are worst affected. However, poverty among urban and nonfarm households also increases due to national food shortages and higher domestic prices.