Our investigation of segment reporting contributes to the empirical literature on discre-
tionary disclosure choices. Empirical tests of voluntary disclosure often aim to test the predictions of theoretical models. The traditional motive offered by the literature to explain
nondisclosure in general (e.g., Verrecchia 1983) and aggregation of segments in particular
(e.g., Hayes and Lundholm 1996) is that disclosure reveals proprietary information. 2 This
motive is also the one most often put forward by managers. For instance, Ettredge et al.
(2002) report that 86 percent of the industrial firms that commented on the Exposure Draft
for SFAS No. 131 opposed the new standard on the grounds that ‘‘it would put them at
competitive disadvantage.’’ It is therefore not surprising that prior empirical studies focus
primarily on examining the proprietary costs of segment disclosure (e.g., Harris 1998;Piotroski 2003; Botosan and Stanford 2005). These papers generally find evidence consis-
tent with disclosure being constrained by proprietary costs.