From the NYT: A Patent Is Worth Having, Right? Well, Maybe Not
"two researchers have analyzed data from 1976 to 1999, the most recent year with complete data. They found that starting in the late 1990s, publicly traded companies saw patent litigation costs outstrip patent profits. Specifically, they estimate that about $8.4 billion in global profits came directly from patents held by publicly traded United States companies in 1997, rising to about $9.3 billion in 1999, with two-thirds of the profits going to chemical and pharmaceutical companies. Domestic litigation costs alone, meanwhile, soared to $16 billion in 1999 from $8 billion in 1997."