The paper reports the results of two controlled-market sessions in which voluntary contributions for the provision of a public good were solicited. The sessions were conducted in an environment comparable to the environment described by Isaac, McCue and Plott (1985) (hereafter, IMP). An important difference in one of the sessions was the use of participants believed a priori to be biased against free riding.
Although the sessions do not precisely replicate the work of IMP, general tendencies found in IMP are obtained. When the production of public goods is required over a number of periods, the use of voluntary contributions as a mechanism for determining the level of production will not result in convergence to a socially optimal level of production. Individual rationality tends to dominate collective rationality. Free riding is an issue. The two sessions reported here, like the existing literature, also indicate that free riding is not complete. Finally, the results of one of the sessions are novel in that they are suggestive of the importance of ideology.
2. The environment and the market participants
The participants in the two sessions reported here were presented with output * We thank the Fall 1985 Economics 3B3 class at McMaster University and the participants in the