We use confidential, U.S. Census Bureau, plant-level data to investigate aggregation in external reporting. We compare firms' plant-level data to their published segment reports, conducting our tests by grouping a firm's plants that share the same four-digit SIC code into a “pseudo-segment.”...

Beginning in 2005, the SEC mandated firms to include a “risk factor” section in their Form 10-K to discuss “the most significant factors that make the company speculative or risky.” This suggests that regulators believe that investors benefit from disclosures about firm risk and...