Trying to determine what things are worth is a huge challenge in today’s business world where companies are increasingly being pressed to account for the changing values of complex financial instruments -- from insurance policies to employee stock options to exotic derivatives. Consequently firms are turning to ever more intricate financial models that attempt to deduce values using an array of indicators even though such models are complicated and can be easily manipulated. This dilemma was the topic of the Tenth Annual Wharton/Oliver Wyman Institute Risk Roundtable held on May 31-June 1.