We argue that much of the prior evidence consistent with the proprietary cost hypothesis
is also consistent with an alternative ‘‘agency cost’’ hypothesis that posits disclosures are
withheld as a result of conflicts of interest between managers and shareholders. Nevertheless,
prior segment reporting papers do not attempt to directly test whether managerial selfinterest
plays a role in segment aggregation decisions. Even in the broader empirical disclosure
literature, scant evidence exists on the agency cost motive for withholding
disclosure.3