Regulation and legislation have failed in the attempt to improve Wall Street company research, at least if accuracy is the measure of success.
After scandals such as Enron and the dot-com debacle, a host of new measures were put in place, most notably 2002's Sarbanes-Oxley Act, which took a hack at reforming company accounts, and 2000's Regulation Fair Disclosure, forcing companies to release material information to all at the same time.
Though earlier studies showed an improvement in the wake of the measures, a new report looking at 1993 to 2013 makes depressing reading.
"Analyst forecast error and dispersion significantly increased over the long-term post-regulation period. Therefore, even if we assume that the regulations caused the improvement in the observed analyst forecast properties in the short run, they did not have a lasting effect," write Hassan Espahbodi and Pouran Espahbodi of the University of Texas Rio Grande Valley and Reza Espahbodi of Washburn University.
Their study, published in the current edition of the CFA Institute's Financial Analysts Journal, shows that although accuracy and dispersion improved in 2003-05, after the new regs were in place, they have since deteriorated significantly.
The regulations were intended to end widespread abuses such as selective disclosure of important information to analysts, as well as practices that gave stock analysts an incentive to put the well-being of their firms' investment banking operations over those of their supposed buy-side clients.
The abuses may have been curbed, but analysts' product did not improve.
"We conclude, therefore, that these regulations did not collectively improve the information environment in the long term, despite the reduction in analyst conflicts of interest. The continued problem with the information environment, therefore, seems to be due to the quality of financial reports," the authors write.
To be sure, the research does not prove that company accounts are less useful, only that analyst estimates based on them are less accurate and more all over the map. Certainly the improvement just after the scandals and regulations may be because attention and criminal prosecution put banks and analysts in fear of putting a foot wrong.