Abstract: | Several bilinear and nonbilinear utility theories are evaluated using individual data from 144 informants. The nonbilinear models are best for 67% of the informants. The nonrational property of duplex decomposition linking joint receipts and mixed gambles of gains and losses is more adequate than the rational link of general segregation for 73% of the informants. The correlations are very high and linear, even in the worst fitting case. The weighting functions are mostly inverse-S-shaped and for 84% of the informants are fit best by the class of functions proposed by D. Prelec. These fits were generally excellent, with a minimum correlation of.81, a maximum of.99, and an average of.97. |