Roberts' participation means the court will not be as short-handed in the upcoming Pfizer cases, in which the court's newest justice, Elena Kagan, is recused. Kagan is sitting out several cases this term because she was involved in them previously when she served as U.S. solicitor general.
The chief justice's involvement, however, means eight justices will hear the two cases, raising the possibility that one or both could result in a 4-4 tie.
Roberts' most recent financial disclosure form, for the 2009 calendar year, indicated that he held $15,000 or less of Pfizer stock, a financial position that has forced him to recuse from previous high court matters involving the New York-based drug maker.
