Gun shows don't contribute to increased homicide or suicide rates, according to results of a study announced Wednesday by the University of Michigan's Gerald R. Ford School of Public Policy.The joint University of Michigan and University of Maryland examination of gun death data in the weeks surrounding more than 3,400 California and Texas gun shows concluded tighter regulation of the flea market-like operations did nothing to reduce firearms-related deaths in the following month.Researchers compared gunshot death data surrounding every known gun show in California and Texas between 1994 and 2004. Researchers say gun-related homicides in the weeks immediately after gun shows in Texas declined slightly.