As U.S. pharmaceutical firms shift a growing number of their drug trials to poorer nations, companies are facing tough ethical questions about what -- if anything -- they owe to volunteers when the tests are done. The quandary is covered in a report from last week's New York Times, which found little consensus among corporate executives about how to handle end-of-trial issues. While some firms continue to provide volunteers with drugs after the tests have concluded, others simply wash their hands of the volunteers, saying the cost of setting up shop in underdeveloped countries is too steep.