Comparability is a central feature of financial reporting systems. Comparability is defined by FASB (2010, 19) as “the qualitative characteristic that enables users to identify and understand similarities in, and differences among, items.” The Accounting Principles Board ranked comparability as one of the most important objectives of financial reporting and Generally Accepted Accounting Principles have underscored the importance of comparability for the past four decades. Using empirical measures of financial statement comparability, studies confirm that comparability plays an important role in analyst following, audit fees, credit risk, acquisition decisions, stock price volatility, the cost of debt, the cost of equity, and cash holdings. This dissertation, investigates the impact of comparability on trade credit, earnings management through classification shifting, and on non-Big4 auditors. Prior studies find that comparable firms enjoy a lower cost of equity capital and a lower cost of debt. They should, therefore, require less trade credit. I also find that comparable smaller and/or financially distressed firms require less trade credit whereas they normally require higher levels of trade credit. The results presented in my first essay support this hypothesis in that comparability and trade credit are significantly negatively associated. The results presented in my second essay show that managers’ earnings management through classification shifting is significantly influenced by the degree of financial statement comparability with other firms. I also find that comparable firms engage in less classification shifting and that the impact of comparability is more pronounced after the passage of the Sarbanes Oxley Act. The results presented in my third essay show that companies audited by non-Big4 auditors are less comparable than the companies audited by Big4 auditors. Non-Big4 auditors are thus less likely to be able to apply the same audit process to multiple clients. I find that this results in greater audit effort, as proxied by higher audit fees, for Non-Big4 firms.