Last week I had a fascinating 3:00 A.M. cab ride from San Francisco airport to a hotel in downtown Oakland. My cab driver was an immigrant from Pakistan who was putting two kids through college. After working for years as a driver he managed to save enough money to buy his own cab, and more importantly to buy the medallion that gives him the right to operate a cab in San Francisco. The medallion cost $250,000. He is still paying $2,300 a month on the loan to get the medallion in an addition to annual fee to the city of $1,500.