We examine the interaction between internal control assessments and substantive testing in a model of fraud detection. The purpose of our study is to examine a two‐stage model of the auditor‐manager interaction in which the auditor assesses the “likelihood” or possibility of fraud in the first stage and conducts substantive tests in the second stage. We examine the allocation of audit resources across these two distinct facets of the audit. We find that, regardless of the auditor's allocation, the probability of undetected fraud remains the same, but the allocation of some audit resources to internal control assessment may provide cost savings for the auditor.

In this study, we provide theoretical guidance for both analytical research and empirical research by considering how changing expectations of earnings affect a dishonest manager's strategy to overstate earnings and an auditor's strategy to exert effort in a two‐period setting. We expect our study's insights on changing economic conditions to help shape future research. We model the manager type as either honest or dishonest, which allows us to differentiate audit risk from audit effort. The key takeaways for future research are the insights on how changes in payoffs and expected earnings affect the associations that involve earnings overstatements and audit effort with audit risk and market price. For instance, researchers typically assume audit effort and audit risk are negatively associated, but we find the association can be positive when, for example, the auditor chooses a period 2 strategy based on the changes in period 1 game parameters. The results of our study provide two additional key insights on the design of future empirical tests. First, by dichotomizing, we show the importance of estimating the intercept in the market pricing equation when studying earnings quality, because market price also adjusts for expected bias through changes in the intercept. Second, our multiperiod setting demonstrates that the effects from a change in the manager's or auditor's incentives in period 1 may reverse in period 2. Empirical studies typically examine the contemporaneous effects of these changes on market price and/or audit risk but fail to identify the cross‐temporal effects we document in our study.