A series of academic studies have drawn a clear line between the consumption of sugar-sweetened beverages and a host of unhealthy outcomes: obesity, diabetes and heart disease. Medical costs for obesity and excessive weight alone are estimated to be about $147 billion - and half of those costs are paid for through Medicare and Medicaid. It's no stretch to say that soda drinking affects us all.
So kudos, then, to San Francisco Mayor Gavin Newsom for taking action. Granted, the action that he's proposing is clunky: a tax on the retailers that sell sugary beverages. The legislation doesn't include restaurants that sell soda, and it sidesteps the most elegant and effective way to reduce soda consumption: Tax the stuff directly, at a penny an ounce. . . .
As for the charge that soda is only one of the major factors contributing to our obesity epidemic, that's true. But the fact that tobacco use is only one of the factors contributing to cancer doesn't mean that we don't tax it for the same reason we should tax soda - when individual people smoke too much, it has an outsize impact on the collective public health.