ABSTRACT
In recent years, much ingenuity has been directed towards understanding collective decision processes; given a set of individuals, each with a clearly defined preference ranking over a set of possible policies, the problem of describing a collective decision, under the imposition of different sorts of decision rules, has been studied both by welfare economists and, more recently, by political scientists. The, by now, classical contribution of Arrow (1951), with his general impossibility theorem, has stimulated many subsequent attempts to get around this apparent paradox. Economists and mathematically oriented social psychologists have paid a great deal of attention to decision-making under risk and uncertainty. The area is one which has, for obvious reasons, attracted the attention of mathematically trained social scientists with the consequence that the theoretical structures are some of the most elegant in social science. However, the empirical success of these various formalistic approaches is something less than satisfactory; when faced with ‘real live ongoing’ collective decision processes, empirical complexity is almost invariably far too rich to be caught by relatively simple models. In so far as any empirical success has been forthcoming, it has usually been at the hands of the experimentalist with comparatively simple group experiments in the laboratory situation.
