Fortunately they are. An article in the Times today described how Ireland has phased out plastic bags. Hippy-minded individuals and businesses such as Whole Foods have begun trying to do the same, but the key is what's stated in the article's title, "Motivated by a Tax, Irish Spurn Plastic Bags." In a town like Austin, maybe there are enough concerned citizens to put a dent in the use of plastic bags, but I don't believe people's concern can be relied on for real change. People will change when it pays to change and this is why wastefulness should be taxed. I can't think of a good reason to use plastic bags, but why not use them? They're free!
What happened in Ireland shows something interesting about conservation. It's the opposite of "you don't know what you got until you lose it;" people sometimes don't realize that some of what they got they can live without. Given that no one uses plastic bags in Ireland anymore, you could argue that Ireland's population could have always got along just fine without them. So, if they could always have got along just fine without them, why did everyone use them for so long? Because they were free! Then they were taxed at 33 cents a bag. According to the article, "Within weeks, plastic bag use dropped 94 percent. Within a year, nearly everyone had bought reusable cloth bags, keeping them in offices and in the backs of cars. Plastic bags were not outlawed, but carrying them became socially unacceptable — on a par with wearing a fur coat or not cleaning up after one’s dog." It's as though Ireland was always a country of conservationists, who just didn't know they were conservationists.
But this sea change ocurred only because of the tax. I think what happened in Ireland should be ammunition for those proposing any tax to encourage conservation or to reduce the use of things that harm the environment. Ireland shows us that it might not be so hard to change and that a tax might not be so bad. I would bet that most Irish don't even think or care about the tax anymore because you'd have to come up with a really good reason to use plastic bags in order to care. Just like you'd have to come up with a really good reason to use a non-hybrid vehicle or an incandescent light bulb to care if taxes made them more expensive than hybrids or CFL's. I can't think of any good reasons, and therefore I think after a few years no one would care about a tax that makes inefficient products more expensive than efficient ones.