Many, if not all, of the recent theories of decision making under risk
, that have been developed in the light of experimentally observed vio
lations of Expected Utility theory, are essentially deterministic in n
ature, yet it is clear that actual decision making contains a random o
r error component. This paper surveys the assumptions that have been e
mployed in previous analyses of such experimental data, and tries to f
ind better explanations (both from an economic and an econometrics poi
nt of view), of such errors. Hopefully, such work will lead to a unifi
ed theory, in which the stochastic component is an integral part.