LogiCIC/LIRa Session: Marcel Boumans

Please note that from April on the LIRa seminar will be held on TUESDAYS.

On TUESDAY, April 2, we will have a joint LogiCIC/LIRa session with Marcel Boumans.

Everyone is cordially invited!

Speaker: Marcel Boumans (University of Amsterdam)
Title: Rational consensus of expert judgments in economics
Date and Time: TUESDAY, April 2, 2013, 15:30-17:30
Venue: Science Park 107 (NEW ILLC LOCATION), Room F1.15

Abstract: The aim of the “rational-consensus method” is to produce “rational consensus”, that is, a “mathematical aggregation”, by weighing the opinion of each expert on the basis of his or her knowledge and ability to judge relevant uncertainties. Over the last fifteen years, Roger M. Cooke has developed procedures to support the formal application of expert judgment. For the kind of cases Cooke has worked on, expert judgment is used to obtain results from experiments and/or measurements, which are physically possible, but not performable in practice. Such experiments are “out of scale” financially, morally, or physically in terms of time, energy, distance, etc. Since these experiments cannot in fact be performed, experts are uncertain about the outcomes, and this uncertainty is quantified in a formal expert judgment exercise. This method should be constrained by “principles for rational consensus”. One of these principles is “Empirical control.” This principle entails the measurement of the performance of the experts by the expert’s assessment of “seed variables.” The disadvantage of the rational-consensus method in social science is the lack of agreed upon seed variables, and that it does not instead use the shared knowledge captured by models. Moreover, there seems to be ample evidence that combining models with expert judgments leads to better judgments. This seems even more evident with respect to forecasts.