  An approach is presented treating decision theory as a probabilistic theory
based on quantum techniques. Accurate definitions are given and thorough
analysis is accomplished for the quantum probabilities describing the choice
between separate alternatives, sequential alternatives characterizing
conditional quantum probabilities, and behavioral quantum probabilities taking
into account rational-irrational duality of decision making. The comparison
between quantum and classical probabilities is explained. The analysis
demonstrates that quantum probabilities serve as an essentially more powerful
tool of characterizing various decision-making situations including the
influence of psychological behavioral effects.
