We study the effects of mandatory disclosure on competitive interactions in the setting of oil and gas (O&G) reserve disclosures by North American public firms. We document that reserve disclosures inform competitors: when one firm announces larger increases in O&G reserves, competitors experience lower announcement returns and higher real investments. To sharpen identification, we analyze several sources of cross-sectional variation in these patterns, the degree of competition, and the sign and the source of reserves changes. We also exploit two plausibly exogenous shocks: the tightening of the O&G reserve disclosure rules and the introduction of fracking technology. Additional tests more directly focused on the presence of proprietary costs confirm that the mandated reserve disclosures result in a relative loss of competitive edge for announcing firms. Our collective evidence highlights important trade-offs in the market-wide effects of disclosure regulation.

The question we address is whether mandated disclosure about dispersion of nonfinancial asset values can provide information relevant to assessing firm risk. Using a sample of Canadian oil and gas (O&G) firms between 2004 and 2011, we find that the difference between the disclosed 10th and 50th percentiles from the O&G reserves distribution, which measures dispersion of the distribution, is positively associated with future total and idiosyncratic equity return volatility, systematic risk, and credit risk. We also find that disclosure of increased reserves dispersion is associated with weaker stock price reactions to increases in reserves and with increases in bid-ask spreads, both of which indicate the disclosures convey information about risk associated with reserves. Additional tests reveal little evidence of managerial opportunism in the reserves disclosures. Taken together, our evidence suggests that quantitative disclosures about the dispersion of nonfinancial asset values can provide information relevant to assessing firm risk.