The purpose of this note is to extend the discussion begun by Castro and Weingarten (1970) in this Journal on the application of experimental techniques to the study of economic behavior. I report the development of special economic systems for human populations, called token economies, that provide potential laboratories for economic experiments.' The results of experiments already conducted in these economies show that changes in wages and prices on job selection and consumption patterns are, in general, in agreement with economic theory. Further, the application of designed experiments to token economies avoids most of the problems currently encountered in dealing with human subjects. A brief description of token economies and summaries of several experiments of particular interest to economists follow. I conclude with a discussion of the advantages and potentialities of designed experimentation in token economies.