Building on willingness-to-pay (WTP) measures as the foundation for applied welfare economics, Just (U. of Maryland), Hueth (U. of Maryland and Universidad de Los Andes, Colombia) and Schmitz (U. of Florida and U. of California Berkeley) develop measures for firms and households where households are viewed as both consumers and owner/sellers of resources. They present possibilities for approximating WTP with consumer surplus, measuring WTP exactly (subject to errors in existing econometric work), and using duality theory to specify econometric equations consistent with theory. Several chapters cover specific areas of welfare measurement under imperfect competition, uncertainty, incomplete information, externalities and dynamic considerations.