&gt;The plastic bag ban caused much gnashing of teeth, but it was a basic instance of market failure (nobody pays for the externalities of bag pollution), and people have adapted fine since the ban took effect.<p>But the ban caused much, much more damage than needed to remedy the externality.  If mispricing were the problem being solved, they could slap an appropriate tax on the stores&#x27; bags, and then stores would pay it, fold it into prices, implement policies to discourage too many bags, roll their eyes, and move on.<p>Instead, the bag law means they must <i>explicitly</i> charge the customer for bags; they can&#x27;t just absorb it into prices (as every store did before).<p>(And I don&#x27;t know if you&#x27;ve ever worked as a cashier, but adding another step to every transaction gets old really quick, and holding up a line so someone can dig for a dime because they forgot to ask for one the first time around is ridiculous.)<p>Furthermore, ten cents is (by any reasonable back-of-the-envelope measure) far more than the magnitude of the externality, and it&#x27;s not put into a fund to remedy the externaliites, nor can I get the ten cents back when I redeem it and thereby prove that it&#x27;s not going into some bird&#x27;s lungs.<p>This is just like most hastily-considered conservation policies: penny-wise and pound foolish.  I&#x27;m likewise hounded to cut back on showers, despite them producing far more economic value than uses of water that are basically value-destructive (growing alfalfa) and which get a free pass.  Similarly, I get paid <i>nothing</i> for having an ultra-low-carbon lifestyle, while people get large government subsidies to make their already-wasteful lifestyle a little less so.<p>Yes, it sucks when externalities aren&#x27;t priced in.  But we shouldn&#x27;t use that justification as carte blanche to overcharge for the wrong ones.