Abbott Laboratories, the patent holder of the antiAIDS drug Norvir, raised the price from $1.71 to $8.57 a day in 2003 (Lauran Neergaard, "No Price Rollback on Costly AIDS Drug," San Francisco Chronicle, August 5, 2004, A4). The price was increased in the United States only when low doses of Norvir are used to boost the effects of other anti-HIV medicines-not in Abbott's own Kaletra, a medicine that includes Norvir. Why did Abbott raise one price but not others?