Welfare change in a CGE model is measured based on the
concept of Equivalent Variation (EV). Intuitively, this approach
assesses how much money has to be provided to (or taken away
from) the household in the base economy in order to leave them as
well off as they are following the irrigation availability shock. So if
the shock hurts the household, then the EV measure is negative,
and reflects a reduction in welfare. Globally, welfare declines by
$3.7 billion with the 95% confidence interval ranging from $2.37
billion to $5.14 billion (2001 prices) as a result of the changes in
irrigation availability between 2000 and 2030. At the global scale
the loss is modest, amounting to 1.44% of the value-added in
irrigated crop production. For the most severely affected regions,
South Asia (excluding India), China and India, the figures are larger