A research team from Harvard, Northwestern and the University of California, Los Angeles, looked at brand-name drugs that also had generic equivalents. When drug companies offered a coupon for the brand-name version, more patients stuck with the more expensive brand-name drug, and the company raised the prices on such drugs faster than it did for drugs for which no coupon was available. Altogether, the researchers estimate that coupons for 23 such drugs with a generic alternative resulted in an extra $700 million to $2.7 billion in spending on drugs over five years.