Margaret Forster , Tim Loughran and Bill McDonald (University of Notre Dame , University of Notre Dame and University of Notre Dame) have posted Commonality in Codes of Ethics on SSRN. Here is the abstract:
We create a database of company codes of ethics from firms listed on the Standard & Poor's 500 Index and, separately, a sample of small firms. The SEC believes that "ethics codes do, and should, vary from company to company." Using textual analysis techniques, we measure the extent of commonality across the documents. We find substantial levels of common sentences used by the firms, including a few cases where the codes of ethics are essentially identical. We consider these results in the context of legal statements versus value statements. While legal writing often mandates duplication, we argue that value-based statements should be held to a higher standard of originality.