Conditions for exact welfare measures in equilibrium displacement modeling are examined. These relate to the functional form of supply and demand, the nature of the exogenous shift, and the definition of percentage changes. Approximation errors when these conditions are not met in empirical...

Accurate and timely measures of cross-country real incomes are still a rarity. As the share of expenditure devoted to food is readily available, we use Engel's law in reciprocal form to measure affluence. Analysis of real income data for over 100 countries indicates that this approach is viable....