How do subjects assess the Social Trade-off. Involved in the Prisoners' Dilemma?

In this paper we obtain the value that experimental subjects attach to a prisoners' dilemma game by applying a related procedure to BDM (1964). We also obtain the value of a closely related game which does not incorporate any social dilemma. By comparing both values, we are able to classify subjects in di.erent categories: (i) 16% of the subjects responded to the social dilemma by playing the cooperative strategy, (ii) The remaining subjects (84%) did not played the cooperative strategy and moreover, 53% of the subjects behaved as if the social dilemma was not an issue at all.