An empirical test for Fishburn's additivity axiom

Three experiments were done to test the empirical relevance of Fishburn's (1967) additivity axiom, which says that people should be indifferent between pairs of gambles which satisfy certain conditions specified in the axiom. Each of the experiments consisted of two parts. In the first part, subjects had to evaluate consequences which were used in the second part as possible outcomes in a gamble. In the second part, subjects had to make choices among pairs of gambles. The experiments differed in respect to kinds of consequences and kinds of subjects used. Additivity analysis was applied to the data of the first part of each experiment, using a conjoint measurement model. A Monte Carlo study is included, which provides some hints for the evaluation of the stress coefficients obtained after applying additivity analysis to the empirical data matrices. The data of the second part of each experiment are discussed in respect to their relevance for Fishburn's (1967) additivity axiom. It was not strongly supported by the data, unless for a very restricted situation.