The amount of money that, paid to a person, group, or whole economy, would make them as well off as a specified change in the economy. Provides a monetary measure of the welfare effect of that change that is similar to, but not in general the same as, compensating variation.
the amount of money that leaves a person as well off as they would be after a change. Thus, it measures the amount of money required to maintain a person's satisfaction, or economic welfare, at the level it would be at after a change.