SAN DIEGO ---- A county-commissioned study estimated that illegal immigrants directly cost the county of San Diego and taxpayers $101 million last year, and indirectly cost an additional $155 million in unpaid medical care. However, the estimates in the $40,000 study, which the county Board of Supervisors voted to pursue in May 2006, were largely based on anecdotal information rather than hard statistics. Supervisors sought the study in the hope of presenting federal officials with a bill for the costs of illegal immigration in the border county of San Diego. Horn and the rest of the board say local governments...