I think Robin exaggerates the extent to which social science would be easier if we could just ask people why they do things. To be sure, there is a tradition in economics that survey results about intentions and ideas (as opposed to age and income!) are not to be trusted. I agree this tradition is overdone and am happy to see work such as Bewley's on why firms hold wages fixed etc. Much of economics, however, concerns effects which are no part of anyone's intention - hence Adam Smith's metaphor of the *invisible* hand. For macro effects of micro behavior there is no point asking people what they intend. No firm intends to push price to marginal cost, no firm intends to use inputs in just such a way that social value of those resources in alternative uses is minimized, no investor intends to impart his knowledge into prices - but this is what happens.
Alex -- Dr. Alexander Tabarrok Vice President and Director of Research The Independent Institute 100 Swan Way Oakland, CA, 94621-1428 Tel. 510-632-1366, FAX: 510-568-6040 Email: [EMAIL PROTECTED]