An effective eye drug is available for $50. But many doctors choose a $2,000 alternative.

Doctors choose the more expensive drug more than half a million times every year, a choice that costs the Medicare program, the largest single customer, an extra $1 billion or more annually, the Washington Post reports. 

Spending that much may make little sense for a country burdened by ever-
rising health bills, but as is often the case in American health care, there is a certain economic logic: Doctors and drugmakers profit when more-costly treatments are adopted.