Earnings and book value are commonly used as the basis for firm valuation. However, the reliability of earnings, as indicated by earnings management, may affect its relevance in determining firm value. This thesis investigates the link between earnings management and firm valuation by assessing the impact of earnings management on the value-relevance of earnings and book value.Three different sources of earnings management are investigated: total discretionary accruals, short-term discretionary accruals, and long-term discretionary accruals. Total discretionary accruals are estimated using the Jones model (Jones 1991). New models are developed to estimate short-term and long-term discretionary accruals. These models enable investigation of the differential impact of earnings management via short-term versus earnings management via long-term discretionary accruals. The primary proposition is that earnings management via long-term discretionary accruals has a greater impact on the value-relevance of earnings and book value than earnings management via short-term discretionary accruals.For firm’s whose discretionary accruals indicate earnings management, the value relevance of earnings is expected to be lower than for firms without earnings management. Moreover, in the presence of earnings management, it is expected that there will be a shift from a reliance on earnings to a reliance on book value in the valuation process. This would be reflected in a decrease in the value-relevance of earnings and an increase in the value-relevance of book value.This thesis provides evidence that earnings management plays a role in the valuation process. A major contribution of this study is the development of models to enable the estimation of short-term and long-term discretionary accruals, thereby extending the earnings management literature by addressing the differential effect of short-term versus long-term discretionary accruals. The results clearly demonstrate that low reliability of information reduces its value-relevance. This link between the integrity of accounting information and its usefulness to market participants supports the need for ongoing regulatory activity to improve the integrity of the financial reporting process.

Earnings and book value are commonly used as the basis for firm valuation. However, the reliability of earnings, as indicated by earnings management, may affect its relevance in determining firm value. This thesis investigates the link between earnings management and firm valuation by assessing the impact of earnings management on the value-relevance of earnings and book value.Three different sources of earnings management are investigated: total discretionary accruals, short-term discretionary accruals, and long-term discretionary accruals. Total discretionary accruals are estimated using the Jones model (Jones 1991). New models are developed to estimate short-term and long-term discretionary accruals. These models enable investigation of the differential impact of earnings management via short-term versus earnings management via long-term discretionary accruals. The primary proposition is that earnings management via long-term discretionary accruals has a greater impact on the value-relevance of earnings and book value than earnings management via short-term discretionary accruals.For firm’s whose discretionary accruals indicate earnings management, the value relevance of earnings is expected to be lower than for firms without earnings management. Moreover, in the presence of earnings management, it is expected that there will be a shift from a reliance on earnings to a reliance on book value in the valuation process. This would be reflected in a decrease in the value-relevance of earnings and an increase in the value-relevance of book value.This thesis provides evidence that earnings management plays a role in the valuation process. A major contribution of this study is the development of models to enable the estimation of short-term and long-term discretionary accruals, thereby extending the earnings management literature by addressing the differential effect of short-term versus long-term discretionary accruals. The results clearly demonstrate that low reliability of information reduces its value-relevance. This link between the integrity of accounting information and its usefulness to market participants supports the need for ongoing regulatory activity to improve the integrity of the financial reporting process.