Andersen implosion over Enron: an analysis of the contagion effect on Fortune 500 firms

The purpose of this paper is to examine how the Andersen implosion over Enron impacted Fortune 500 firms that were competitors of Enron and/or audited by Andersen. This event provides an opportunity to study various contagion effects.

An event study methodology is used to analyze the immediate financial impact of the Andersen implosion on competitors of Enron and/or firms audited by Andersen. More specifically, how did the announcement of the implosion impact these firms?

The results support a strong industry contagion effect where Enron's failure benefited the surviving energy/utility firms who could then increase their market shares. The authors find the energy/utility firms not audited by Andersen, on average, experienced an astounding 2.5 percent increase in market capitalization when the audit scandal was announced. In dollar terms, the mean and median market capitalization increases were $226 million and $101 million, respectively. In the aggregate, the 21 utility/energy firms gained $4.76 billion in market capitalization.

The results show the importance of the auditing process and the impact of unethical actions on the firm, their auditor, and their competitors. One limitation is the data are limited to large Fortune 500 firms.

This is the first study, to the authors' knowledge, that evaluates the contagion effect of the Andersen/Enron audit scandal on Fortune 500 firms: in the same industry as Enron; audited by Andersen; and operating in the same industry as Enron and audited by Andersen.