Abstract. The purpose of this study is to examine the information content of the components of the annual change in the quantity of proved reserves reported by U.S oil and gas (O&G) producers. In particular, it investigates the contemporaneous association between the unexpected portions of discoveries, production, net purchases, and revisions of prior quantity estimates and unexpected security returns during the release week of the 1984 to 1988 annual reports or forms 10‐K of these firms. The empirical results suggest that (1) disaggregating the net change in the quantity of proved reserves into its components conveys additional information beyond that contained in the net change in total proved reserves itself, (2) discoveries are highly associated with security returns even after controlling for production, and (3) revisions, net purchases, and production have a modest influence on security returns. The findings of this study are interpreted within the context of the economic environment of the O&G industry during the test period. Résumé. L'auteur examine le contenu en information des éléments du changement annuel de la quantité de réserves prouvées dont font état les producteurs pétroliers et gaziers des États‐Unis. Il s'intéresse en particulier, pour la période 1984–1988, à l'association que l'on établit maintenant entre, d'une part, la portion inattendue des découvertes, la production, les achats nets et la révision des estimations antérieures de quantité et, d'autre part, les rendements imprévus des titres au cours de la semaine de publication des rapports annuels ou des formulaires 10‐K des entreprises. Les résultats empiriques donnent à penser que (1) la décomposition en ses différents éléments du changement net dans la quantité des réserves prouvées livre davantage d'information que le changement net global lui‐même, (2) les découvertes sont associées de très près aux rendements des titres, même une fois contrôlée la variable production, et (3) les révisions, les achats nets et la production ont une modeste influence sur les rendements des titres. Les résultats de cette étude sont interprétés dans le contexte économique du secteur pétrolier et gazier au cours de la période d'analyse.

ABSTRACT This study provides evidence of a directly observable and significant cost of International Financial Reporting Standards (IFRS) adoption, by examining the fees incurred by firms for the statutory audit of their financial statements at the time of transition. Using a comprehensive dataset of all publicly traded Australian companies, we quantify an economy-wide increase in the mean level of audit costs of 23 percent in the year of IFRS transition. We estimate an abnormal IFRS-related increase in audit costs in excess of 8 percent, beyond the normal yearly fee increases in the pre-IFRS period. Further analysis provides evidence that small firms incur disproportionately higher IFRS-related audit fees. We then survey auditors to construct a firm-specific measure of IFRS audit complexity. Empirical findings suggest that firms with greater exposure to audit complexity exhibit greater increases in compliance costs for the transition to IFRS. Given the renewed debate about whether the Securities and Exchange Commission (SEC) should mandate IFRS for U.S. firms, our results are of timely importance. Data Availability: Data are publicly available from the sources identified in the paper. Survey response data are available from the authors upon request.